The United Kingdom of Great Britain and Northern Ireland has a national parliament with an internationally used metonym Westminster after the City of Westminster, London, where the parliament is located (or perhaps after the Palace of Westminster, which is in turn named after the City of Westminster).
The devolved parliament for Scotland is often referred to as Holyrood after the Edinburgh area of Holyrood (Brexit talks divide opinion between Holyrood and Westminster)
The Northern Ireland assembly is often called Stormont after the Stormont estate (Stormont failure over gay pardons 'a disgrace').
The National Assembly for Wales is located in a building called the Senedd in Cardiff. I'm not sure what the neighbourhood of Cardiff is called.
The word senedd is simply Welsh for senate and therefore not a metonym. Is the word Senedd word used for the National Assembly for Wales? Is there any metonym in use? If so, which one?
Searching far senedd at
site:news.bbc.co.uk yields very few results, and a large fraction are about the senedd building rather than about the assembly as an institution.