A castle may not be the first place that you think of when looking for fossils, but Pembroke Castle is built of local Carboniferous Limestone, which, over the centuries, has been weathered to reveal their fossil contents.
♦ Look for signs to the castle (the SatNav address to use is SA71 4LA).
♦ Abundant parking can be found in pay and display car parks close to the castle.
♦ Ref: 51.64523°N, 4.80186°W
FIND FREQUENCY: ♦ – Many of the castle’s building blocks are composed of crinoidal limestone. Some of these have weathered slowly and delicately over hundreds of years to bring their fossils into high relief, showing immaculate detail.
CHILDREN: ♦♦♦♦♦ – This is a tourist attraction and, as such, caters for all members of the family. While the fossil hunters are staring at rocks in the walls, the rest of the party can enjoy a fascinating and educational day out.
ACCESS: ♦♦♦♦♦ – The castle is within the town centre with plenty of pay and display parking to be found nearby. Most of the staircases within the various parts of the building are steep and young children should be supervised when climbing and descending these. The castle is open all year round, seven days a week. Opening times vary – see the castle’s website for details and for details of admission prices.
TYPE: – Pembroke Castle gives the fossil hunter a chance to see what the fossiliferous limestones of the area look like when naturally weathered over hundreds of years.
Once inside the castle, there are plenty of rooms to explore and many walls to examine for fossils. A video at the beginning of the castle tour takes you through its colourful (human) history.
The crinoid fossils within the blocks that were quarried more recently during one of the castle’s numerous periods of repair have only been exposed to weathering for a relatively short period of time and do not stand proud of their matrix. However, blocks within the walls of the oldest parts of the castle have had many hundreds of years for their fossils to weather free of their matrix and these are seen in high relief. These fossils are beautifully displayed and the natural weathering has prepared them in a way that a skilled fossil preparer would be proud of. These naturally weathered blocks are a real treat and show what the rocks of our coastlines and other rocky areas must have looked like before we became aware of the significance of fossils and started to collect them.
Crinoid stem parts are the most abundant fossils seen, but corals and brachiopods are also present. Most building blocks of the castle are fossiliferous, so look in all outside walls for fossils. The oldest surviving part of the castle is found within the inner gatehouse and keep area. It is here that the most spectacular effects of weathering are seen, with some truly beautiful fossil assemblages on show. Also look in the stone steps of the various towers for fossiliferous blocks that have become polished over the years by people’s footsteps. Some indication of the age of the towers can be gleaned from the degree of polishing of the steps within.
The provenance of the rocks making up the castle is difficult to ascertain, but most (if not all) come from (Lower) Carboniferous Limestone Supergroup of the immediate area.
Children should be supervised when climbing the steep staircases within the towers. Otherwise, this is a safe location.
Fossils cannot be collected from this site, but take a camera or smartphone to photograph the ones you do see. In addition, a hand lens will allow you to inspect the fossil more closely.
Privately owned, an admission fee must be paid to gain entry.
This site is an SSSI. This Special Site of Scientific Interest, means you can visit the site, but hammering the bedrock is not permitted.