It shows Sultan Omar Ali Saifuddin Mosque, a royal Islamic mosque located in Bandar Seri Begawan, the capital of the Sultanate of Brunei. The mosque is one of the most spectacular mosques in the Asia Pacific and a major landmark and tourist attraction of Brunei. Named after Omar Ali Saifuddien III, the 28th Sultan of Brunei, the mosque as a symbol of the Islamic faith in Brunei dominates the skyline of Bandar Seri Begawan. The building was completed in 1958 and is an impressive example of modern Islamic architecture.
The stamps I know nothing about, although the man looks like Hassanal Bolkiah, the Sultan of Brunei.