Monnow Bridge in Monmouth, is the only remaining fortified river bridge in Great Britain with its gate tower standing on the bridge. Such bridge towers were common across Europe from medieval times, but many were destroyed due to urban expansion, diminishing defensive requirements and the increasing demands of traffic and trade. The historical and architectural importance of the bridge and its rarity are reflected in its status as a Scheduled Monument and a Grade I listed building. The bridge crosses the River Monnow 500 metres above its confluence with the River Wye.
Weathering is the process where rock is dissolved, worn away or broken down into smaller and smaller pieces. Once the rock has been weakened and broken up by weathering it is ready for erosion.
Erosion happens when rocks and sediments are picked up and moved to another place by ice, water, wind or gravity. In this case it is water.
Wave erosion is the wearing away of material from a coastal profile. Waves, generated by storms, wind, or fast moving motor craft, can cause this erosion, which may include losses of sediment and rocks, or just the temporary redistribution of sediments
Limestone is a sedimentary rock. Historical information as well as buildings still standing such as this gatehouse point to limestone as a very durable and time-tested building material.
To complete this EarthCache, you need to answer the following questions:
1)Describe the texture of the rocks on the outside of the outside of the arch compared to in the archway
2)Describe and explain the impact that the river is having on the base of the bridge
3)Using the info boards by the steps, describe the colour change from when the initial arch was built to what you see now.
Please send your answers at the same time as you log the cache. We will reply as soon as possible.