 But even with a new grid town plan the architecture of the town remained modest, mainly single-storey buildings.However, the development in Helsinki's architecture came after 1748 with the construction of the Sveaborg fortress - nowadays a World Heritage Site - (first planned by Augustin Ehrensvärd) on a group of islands just off the coast from Helsinki; the heart of the fortress was a dockyard, but distinct Baroque architecture as well as an English-style landscape park were placed within the otherwise unsymmetrical fortification system, all built in stone and brick, and many of the "windows" in the classical facade compositions were in fact painted on.The architecture of the buildings was in a restrained Rococo classicism named after the influential Swedish architect Carl Hårleman(1700-1753).