The almost 2 mile long Holyhead breakwater, built between 1845 and 1873 to provide protection to Holyhead harbour so that its use as a port for Irish traffic could be increased. The straight road on the right is the route of the former breakwater railway, used to transport stone from quarries on Holyhead Mountain for building up the breakwater.
The ENSCO 85 jack-up rig is a Marathon Letourneau 116C design built in Singapore in 1981. See http://www.offshore247.com/projects/rigdetails.aspx?rid=12 for fuller details. This type of drilling rig has been used to develop the natural gas fields in the East Irish Sea.