The ancient name of Pietra Ligure was La Pietra , and referred to the imposing calcareous rock that is found to the east of the historical center, above which the Roman castrum was built. The castle, enlarged in the period of the barbarian and Saracen invasions (6th-9th century), was a bishop ‘s property and reached its present size in the 16th century. It is believed that this natural barrier, easily defensible, constituted a border point between the Byzantines and the Lombards .
The Byzantine castrum was probably destroyed by King Rotari, but in the same site the medieval castle, stronghold of the bishops of Albenga, was built in the 12th century , subject then to frequent attacks by the Del Carrettos of Finale . To the west of the castle a hamlet developed, surrounded by turreted walls and endowed with five gates: the port of the marina protected by a bastion to the south, the gate of Santa Caterina near the homonymous rural oratory to the north, the door of the porch protected by the tower of via Rocca Crovara and the royal gate to the west, the door to the slaughterhouse to the east. After various vicissitudes, the village was definitively ceded by Pope Urban VI to Genoa , in 1385 , and acquired considerable importance as an advanced point of the Republic between the Finale and Loano , fiefdom of the Doria .
The castle remained the property of the bishops of Albenga, who sold it to the Arnaldo at the end of the fourteenth century . It then passed into the possession of other patrician families and was enlarged in 1550 with the addition of a wing facing south-west, an arch in the eastern part in addition to the two sentry boxes. Due to the Saracen raids the upper square was armed with two large cannons, which were sent back to Genoa at the end of the 18th century in view of the French invasion. The medieval part, at the end of the fifties of the twentieth century , has been restored and transformed into a meeting place. The solid masonry resting directly on the rock, the impervious position, the vaulted passages and the low rooms of the dungeons known as “Grimaldina”, due to the fact that two Grimaldi brothers from Monaco were imprisoned there at the end of the fourteenth century, justify the importance of the castle exercised in the local defense system.References:
German crusaders known as the Livonian Brothers of the Sword began construction of the Cēsis castle (Wenden) near the hill fort in 1209. When the castle was enlarged and fortified, it served as the residence for the Order's Master from 1237 till 1561, with periodic interruptions. Its ruins are some of the most majestic castle ruins in the Baltic states. Once the most important castle of the Livonian Order, it was the official residence for the masters of the order.
In 1577, during the Livonian War, the garrison destroyed the castle to prevent it from falling into the control of Ivan the Terrible, who was decisively defeated in the Battle of Wenden (1578).
In 1598 it was incorporated into the Polish-Lithuanian Commonwealth and Wenden Voivodship was created here. In 1620 Wenden was conquered by Sweden. It was rebuilt afterwards, but was destroyed again in 1703 during the Great Northern War by the Russian army and left in a ruined state. Already from the end of the 16th century, the premises of the Order's castle were adjusted to the requirements of the Cēsis Castle estate. When in 1777 the Cēsis Castle estate was obtained by Count Carl Sievers, he had his new residence house built on the site of the eastern block of the castle, joining its end wall with the fortification tower.
Since 1949, the Cēsis History Museum has been located in this New Castle of the Cēsis Castle estate. The front yard of the New Castle is enclosed by a granary and a stable-coach house, which now houses the Exhibition Hall of the Museum. Beside the granary there is the oldest brewery in Latvia, Cēsu alus darītava, which was built in 1878 during the later Count Sievers' time, but its origins date back to the period of the Livonian Order. Further on, the Cēsis Castle park is situated, which was laid out in 1812. The park has the romantic characteristic of that time, with its winding footpaths, exotic plants, and the waters of the pond reflecting the castle's ruins. Nowadays also one of the towers is open for tourists.