NOTES: Castel Sant'Angelo was originally constructed as a mausoleum for the Emperor Hadrian in 135-139 AD. The bridge, built at the same time to connect the mausoleum to the Campus Martius, was named Ponte Elio (Pons Aelius). When the mausoleum became a castle in 401 AD, it was renamed Castel Sant'Angelo and the bridge took the same name.
NOTES: The cathedral, the largest Romanesque church in Italy, was built between 1063 and 1118. The adjacent Bapistery of St John replaced an older baptistery and was begun in Romanesque style in 1152 under Diotisalvi. The upper part underwent a Gothic transformation by Nicola Pisano and his son, Giovanni, in 1277-1297. The dome was added by Cellino di Nese in the 1300s and the building was finally completed in 1363.
NOTES: Construction on this country residence of the Russian Imperial family began c.1780 and was completed c. 1825. Its design was typical of the country mansion of the period and was created by a succession of architects, painters and sculptors, notably Charles Cameron who designed the central Great Palace in 1782-1786.