After St Mary-de-Lode church, turn left into Archdeacon Street. Head down towards the end of the street then bear left into Westgate Street. Opposite St Nicholas's Church (which, incidentally, has a leaning tower) is Nicki's Taverna. The marble-like stone beneath the windows has an amazing pattern. This is Rapakivi granite and has large round feldspar crystals in cross-section. It's probably the oldest rocks we'll see on this walk, dating from Precambrian times (543 million years ago to 4500 million years ago!). What's so special about this granite is that it's a metamorphic rock - it solidified after an original melt, remelted and then recrystalised.

Shire Hall on Westgate Street

Continuing up Westgate Street towards The Cross, our next stop is Shire Hall. Here we'll see two very different stones which offer valuable insights into geological history. The front of Shire Hall, designed by Sir Robert Smirke in 1816, is made from Pennant Sandstone from the Forest of Dean. This stone began life being deposited in carboniferous coal swamp deltas about 295 million years ago. You'll notice that there is some red staining on various blocks - this is due to iron oxide in the stone. Also, you'll see pebbles embedded within the sandstone at various points. These stones are called Siltstone and are less resistant to weathering, which is why some of them have disappeared completely.

Facing Shire Hall, head right and follow the building around to the side. You'll now see the modern part of the hall, added in the 1960s. The materials used here document a violent time in Britain's history, for the green panels that stretch down the side of the building were once volcanic ash deposited in the Lake District. This happened about 460 million years ago in the Ordovician Period. In some panels you can see the layer of ash from one eruption followed by another layer of ash from a subsequent eruption.

Return to Westgate Street and resume your journey up towards The Cross. The last stop before you reach The Cross is the Halifax building society on your right. This building is faced with a material called Serpentinite.

Finally you've returned to The Cross and the end of this walk. The Cross is the meeting point of the four main streets that follow the original Roman foursquare plan laid down around 45AD. Gloucester city centre was subsequently developed by following civilisations but the original Roman design of four-squares from The Cross still holds true.

...And now you've completed the short walk around Gloucester city centre. If you have any comments to make or would like to send any Gloucester Trail pictures in, please visit the Feedback page.