This kind of expressions of secular and economic power are also found in other late mediaeval commercial cities, including the Llotja de la Seda of Valencia, Spain, a purpose built silk exchange dating from the 15th century, in the partial remains of Westminster Hall in the Houses of Parliament in London, or the Palazzo Pubblico in Siena, Italy, a 13th-century town hall built to host the offices of the then prosperous republic of Siena