In Ireland, there are examples of lighthouses bein built on the same site as original lighthouses (Fastnet, Ferris Point, Ardglass etc)
There are also many examples of lighthouses being built very close to existing lighthouses, Wicklow Head, Loop Head, Clare Island, to name but three.
But, off the top of my head, ( a part of my body diametrically opposite another part that I often speak out of) there have only been two examples in Ireland of lighthouses having been moved from one location to another. This has happened in England and in the US, normally when coastal erosion has threatened a particular lighthouse.
The two are Roches Point Lighthouse in county Cork which was taken down in 1838, transported to Wexford and rebuilt as the Duncannon Rear Light.
The other one is the North Wall Quay on the northside of the River Liffey in Dublin.
The original lighthouse here was built in the early nineteenth century (see previous post)
The rapid development of Dublin as a port was down to the foresight and hard work of one man, Bindon Blood Stoney, in the mid nineteenth century. Large areas of marshland were reclaimed, a Breakwater (with light) was built to facilitate the port's expansion and a quay was built, extending from the existing North Wall quay, almost enclosing the new Alexandra Basin.
The harbour works were completed in 1884. One presumes that a light of some sort must have been erected at the end of the North Wall extension but the current lighthouse only went up in either 1902, 1904 or 1908, depending on which source you go by. It is cast iron and stands 39 feet above the end of the pier in a highly-restricted area.
The pier was extended to provide extra berths both inside and outside the basin and the lighthouse was moved to the end of the pier extension in 1937, where it has remained ever since (see map below, showing 1930s proposals for the pier extension)
It now appears that the lighthouse may be on the move again, which I reckon would be some kind of global record for a fully-working lighthouse. It appears that the North Wall Quay extension is planned to be shortened, roughly back to its pre-1937 location. And, in line with modern observances of industrial heritage, the lighthouse is to be lifted up and plonked down at the end of the new, shorter pier, along with the granite stones it sits on.
And the good news is, Dublin Port plans to make the lighthouse a heritage site, with access to the lighthouse free to the public, though on an appointment, rather than an ad-hoc basis.
Above and below, some pictures of the lighthouse interior.