Fowey on Wikipedia.
 

The Rashleigh Mausoleum stands somewhere near the site of the long vanished St. Catherine's Chapel, mentioned in 1315. SX 118 509. © Paul E. Barnett (2016). Link.

St. Fimbarrus (St. Nicholas in Pevsner) has had a chequered history. Dedicated to St. Fimbarr, a sixth century saint, the original church was replaced by the Normans. Relatively little remains; the town was attacked by the French in the 1457 and the church destroyed. It was rebuilt in 1460. SX 125 517. © Robin Pizzy. Another view, © Bill Henderson (2009). Two interior views - 1, 2, a slab commemorating a knight, and a tomb, the font, pulpit, and a side-aisle window, all © Steve Bulman (2010). Another view of the font, © Paul E. Barnett (2017). Link. According to this history, the original dedication was to St. Barry. Grade I listed.

Former Wesleyan Church, on Fore Street and Passage Street, now converted into flats. It dates from 1894. SX 126 518. © Andrew Ross. Another view, © Paul E. Barnett (2015).

This former chapel sits at the bottom of Lostwithiel Street. Can you give it a name? Now flats. SX 1253 5165. © Andrew Ross. Howard Richter has advised me of this link which says that it was a Congregational Chapel. Assuming this is correct, then it will have been Mount Zion Independent Chapel, founded 1797, although the building is evidently later than this.

A former church, marked on OS maps as St. Monica's. But as Andrew says, it doesn't look quite right for an old chapel. It stands on Passage Street and Station Road at SX 1266 5219. © Andrew Ross. Rob Brettle had suggested that it may formerly have been the Salvation Army Hall. Whether it had been S.A. at one time, as St. Monica it was Roman Catholic, as Howard Richter found in a 1932-3 travel guide to the area. It's now in use as a holiday rental (link1, link2).