In the 1990s, many of the districts were renovated and projects in the historic quarters were established to modernise those areas, for instance, architectural and patrimonial buildings were renovated, the northern margin of the Tagus was re-purposed for leisure and residential use, the Vasco da Gama Bridge was constructed and the eastern part of the municipality was re-purposed for Expo '98 to commemorate the 500th anniversary of Vasco da Gama's sea voyage to India, a voyage that would bring immense riches to Lisbon and cause many of Lisbon's landmarks to be built.