We returned from a hard-earned day off, back to the woods of Forty Hall today, and our diggers' hard work has begun to reveal some increasingly interesting, and typical for for the site of Elsyng Palace, enigmatic features.

We ended day 8 in Trench 2 having revealed an asymmetric brick surface, partially laid obliquely over a wall at its north end, and perpendicular to the foundations of another at its south end (the two walls likely meeting to form a corner in a trench we dug last year). This was further complicated by a deliberately filled slot at the floor's north end, and possibly another at its south end. See day 7 for pictures.

We started the day today by removing non-structural rubble from around the southern wall, and it now looks like the southern of the two slots through the floor was an illusion, and the floor in fact abuts the south wall.

However, removing rubble in the south-east corner of the trench revealed a surprise - a hole has opened up into a sizeable void beyond the south end of the trench.

It's just about big enough to get a camera into, and as far as we can see it is lined with a curved brick face to a depth of at least 9 or maybe 10 courses - a depth of about 60cm.

The roof of the chamber is either loose rubble or very haphazardly mortared brick fragments - it is possible that there's a better-built roof to it above.

We have therefore opened a 2x1m extension over the top of it and have removed topsoil and most of the ubiquitous pebble context that covers the whole area. We've just begun to reveal the rubble layer that likely lays on top of whatever this feature is, and will have to devise a careful excavation strategy tomorrow to avoid loosing one of our diggers into the chamber headfirst!

Meanwhile at the other end of the trench we opened a similar extension, aiming to reveal more of the other wall and hopefully the north end of the brick floor - due to their oblique angles relative to one another the edge of the floor and wall should come together somehow somewhere not far away.

We again got as far as the beginning of the rubble deposit, although some of it looks as if it is in-situ, possibly meaning that the structures are not demolished as deep at the north end of the trench.

The most interesting find of the day was a chunk of yellow-glazed floor tile from Trench 3 which is still being dug down to the level of the expected wall junction.

We have seen plenty of glazed floor tiles before but never one with graffiti scratched onto it. This one has a series of overlapping circles scratched onto its reverse side.

Circle-based geometric designs are a common form of graffiti, and are often found in buildings (especially churches) in England, from the early medieval period up until the 19th century.

Sometimes known as "witches marks", their meaning or purpose, if any, is disputed - see https://historicengland.org.uk/whats-new/features/discovering-witches-marks/what-are-witches-marks/ for more information.

Whether a secret symbol deliberately placed beneath a floor to ward off evil, or a bored apprentice with a pair of dividers, it's a nice human touch we very rarely see on ordinary building materials.

No significant developments to report on day 8 of our two week dig on the site of Elsyng Palace.

We spent most of the day making detailed plans, surveying and photographing the brickwork in Trench 2.

We're still not sure what the purpose of the brick floor is in T2, nor the two apparent channels at either end of it. We don't think it's likely that they are drains, since they don't seem to lead to or from anywhere, so the balance of evidence at the moment points to slots for timber beams.

Having studied the mortar of the walls at either end of the trench (see the diagram from yesterday) we think they date to the early 16th century phase of the palace, when it was remodelled by Sir Thomas Lovell.

Since the floor is laid on top, it must post-date that phase and so may be part of the work done in the early 17th century, when the palace was again remodelled and reduced in size by James I, before it was given as a grace-and-favour home to his friend the Earl of Pembroke.

This is all still very speculative, and in order to understand it better we want to see more of the structure, particularly at the north end of the trench.

As often happens we've unfortunately placed a spoil heap slightly too close to the trench to extend in that direction so we bit the bullet and spent part of the afternoon moving it out of the way.

We still have two other trenches open - T3 which will eventually come down onto the wall junction we saw last year (see Day 1), and T4 over at the western end of the site, in search of the 1960s trenches.

Work in both these trenches has become hard-going as they've had a long time to bake in the hot and dry conditions.

Trench 4 has almost certainly not hit any 1960s backfill, but there is a deposit of very compacted brick rubble in one corner and it has begun to produce some small finds, including a few very striking fragments of "Westerwald" stoneware - probably a jug - decorated with a brilliant cobalt blue glaze.

Westerwald pottery comes very late in the chronology of Elsyng - in this case most likely dating to the mid-17th century - and so this vessel would have been amongst the last high quality tablewares imported onto the site before its final demolition circa 1660.

This and a few other finds in Trench 4 further point to its never having been dug before. We will fully excavate this trench but it looks probable now that we won't have time this year to open any more trenches targeting the 60s work.

Monday is our day off, but we'll be back on Tuesday to wrestle the remaining secrets from our open trenches.

A busy day today as we come to the end of the first week of our two-week dig in Forty Hall on the site of Elsyng Palace.

Today was our public open day, and we were pleased to welcome a steady stream of visitors all day, who joined us in scratching their heads at the impressive but somewhat enigmatic medieval/Tudor brickwork that was emerging from Trench 2.

Once we'd set up our displays and stalls, we finished exposing the brick floor in Trench 2, fully defining the edge of the wall that runs partly beneath it on its east side.

We also removed the rubble at the south end of the trench, which as expected revealed another wall under it. During this process it began to look as if there is another channel cut through the floor, although this one seems to have rubble in it rather than tiles like the other one - see the image to the right, and click here for an annotated version.

So, in this trench we currently have a brick floor surface, bounded on the south side by a wall, and with two parallel slots through it, with a second wall running partly beneath its east edge.

Since the floor is partially laid on top of it, the wall must pre-date the floor. The wall may therefore belong to the early 15th century phase of the palace as built by the Earl of Worcester, with the floor representing the extensive improvements made by Sir Thomas Lovell after his acquisition of the palace circa 1497.

Exactly what the floor and the channels are for is not yet clear. All this brickwork is along the back edge of the gatehouse, so we might expect the threshold to a rear entrance. In this case, the parallel channels may be the remains of beam slots that once supported a timber frame for something like a porch.

This theory was slightly confounded very late in the day, as we began to remove the jumble of roof tiles from the northern channel, only to find more tiles beneath, tightly mortared together. This begins to look as if the channel has been hastily and crudely blocked up - which you might expect of a drainage channel that went out of use.

There's still plenty more work to do on all of this to make things clearer, and a whole week to do it, including the continuing search for evidence of the 1960s trenches. Work continued in Trench 4 to that end today, and it is beginning to look unlikely that it contains 1960s backfill.

A day of excitement in Forty Hall today, but sadly for the wrong reasons.

A large grass fire broke out this afternoon on the east side of the lime tree avenue and rapidly spread, alarmingly initially towards the dig site.

A fortunate change in wind direction eventually carried the fire away to the east towards Maidens Bridge, before the London Fire Brigade arrived and were able to get it under control before it spread to any major groups of trees.

The first fire engine arrived very quickly and we were able to assist it onto the site, where its crew did an excellent job dousing the main flames, but a second engine was delayed by another call en-route, so EAS members lent a hand beating out and dousing smoldering hotspots with buckets of water from Maidens Brook, while the fire crew handled the main flame front.

Once the second engine arrived everything was quickly put out and the crews spent most of the rest of the day damping down the scene.

Meanwhile, back at the archaeological dig:

Just before all the excitement, we had just opened our fourth trench, about ten metres to the west of Trench 1, in another attempt to identify the complex of trenches first dug by the EAS in 1963-66.

This is as far west as we can go this year, and on the face of the available evidence we don't think the 60s work can have been significantly further west than this. If this trench draws a blank as Trench 1 did, we have a couple more options nearby, but our chances of finding the 60s work this year would start to seem really very slim, and we would need to seriously re-appraise our evidence for where the 60 work took place.

Things were much more optimistic in Trench 2, however, which is now rapidly producing a rich assortment of brickwork.

The rough brick surface we began to reveal yesterday is now almost entirely revealed, with a distinct edge along its west side. Where it enters the east section of the trench there is a rough tumble of bricks which may or may not be concealing a wall beneath. Just before it enters the west section (foreground of above image) there is a stack of tiles which look to be filling a slot through the surface. We can't tell yet if this is deliberate, for example a collapsed drain, or a coincidental tumble.

Along the east side of the brick surface (upper left in above image) there seems to be the remains of a wall, running on a different alignment to the surface, and we think beneath it (i.e. the brick surface is later and built on top).

There is a lot of work to do to make sense of all this and a lot of careful unpicking of rubble still to go, but the next major job in this trench will be planning and photography tomorrow morning, that is after we've set up all the gear for our public open day.

Let's hope it's not as much of a scorcher as today.

Day five of our two-week dig saw us turn away for the time being from our primary aim of relocating trenches dug in the 1960s, to our two secondary objectives, studying elements of the palace gatehouse building that we discovered last year.

Having proved yesterday that Trench 1 does not contain any evidence of 60s trenches, and not being able to safely dig any deeper into the rubble deposit due to the risk of section collapse, we have more or less done all we can in that trench for now.

We therefore redeployed our diggers to our secondary objectives. Trench 3, at the north side of the site, is intended eventually to reveal more of a wall junction seen last year, but for now there is still a fair amount of gravel and rubble to remove before we can expect results from it.

Meanwhile Trench 2, which has had a head-start, had the last of its post-palace landscaping pebbles removed early in the morning. Late yesterday afternoon we had got a hint of the anticipated brick surface, and sure enough as the afternoon wore on the few bricks we saw yesterday did indeed acquire several friends.

We haven't revealed the whole of the brick surface yet but it does seem to have at least one edge, which seems to be running towards where the expected wall ought to be. We're probably not deep enough to see the wall yet, so there remains plenty to do to understand this feature properly.

Apart from the masses of late 19th and early 20th century rubbish in Trench 1, there hasn't been a great deal in the way of finds so far but an eagle-eyed digger did spot a rather nice probably Mesolithic tool (probably a tool for piercing leather and/or animal skins) amongst the gravel being removed from Trench 3.

Quite a morale-booster and a reminder that hunting had been going on in Enfield for several thousand years before the Tudors.