Hi there
The Mwldan was/is an area in Cardigan off the High Street/Pendre. It has a stream of the same name running through it which had its outlet into the river Teifi, the main river on which the town was built.
At this time the area was very crowded and a lot of people living in it were employed in the trades associated with Cardigan's shipbuilding industry - sailmakers, carpenters, millwrights etc. It was also fairly close to the Workhouse and gaol.
At some stage the area was cleared of its slums, and these days a large car park behind the town hall covers the site, together with the Theatre Mwldan - there was also a clothing factory in the 1980's making clothes under the Slimma brand, which has long since closed.
Check out the local town's museum website and for local history publication published by the Teifiside Advertiser.
St Mary's Cardigan is the registration district for the whole town. The parish church of Cardigan is St. Mary's and has a huge churchyard. The local Cardiganshire FHS publishes MI's for it. Cardigan also has a large number of non-conformist chapels. The municipal graveyard is called Netpool.
Hope this offers some clues?