The Exchange and Assembly Rooms
The impressive building standing where North Street, Bridge Street and Waring Street meet was originally Belfast's Exchange and Assembly Rooms. Continue along North Street and enjoy its many 19th and 20th century buildings. At its upper end, look for the magnificent twin towers of St. Peter's Cathedral and follow them to their source off Albert Street.
The Ulster Bank building on Waring Street is one of the most impressive edifices in Belfast. It stands opposite Cotton Court, a converted cotton warehouse. Nearby, the War Memorial Building, opened in 1963, pays tribute to Northern Ireland's wartime efforts.
There are numerous shopping opportunities in and around North Street. The Gallery, off Rosemary Street offers a mix of bijou stores and nationals, with CastleCourt on Royal Avenue and Victoria Square on the corner of Chichester Street and Victoria Street, there's bound to be something for just about everyone.
Alternatively, if architectural heritage is your thing, then check out some places of interest on High Street. Budding sleuths will appreciate the St. George's Building, one-time home to the Ulster Overcoat Company, makers of the Sherlock Holmes' famous overcoat. For comparison, see the austere modernism of Transport House. St. George's Church on High Street stands on an ancient ecclesiastical site and is an architectural delight.
There is an excellent guide to Belfast's historical buildings available in pdf format from Belfast City Council
There are two other cache's close by that you may be interested in visiting, one is Black Santa's Sit Out which you'll find very close to St. Anne's Cathedral and the other is Busman's Holiday - Laganside Belfast. There are, of course, many more caches in the city centre but these are the closest two from here.