The Mosque of Cristo de la Luz is a former mosque in Toledo. It is the only one of ten that once existed in the city that remains largely as it was in the Moorish period. Legend has it that a shaft of light guided the king to a figurine of the crucified Christ that had been hidden for centuries. He left his shield there with the inscription, 'This is the shield which the King Alfonso VI left in this chapel when he conquered Toledo, and the first mass was held here'.
In 1186, Alfonso VIII gave the building to the Knights of the Order of St John, who established it as the Chapel of the Holy Cross (Ermita de la Santa Cruz). It was at this time that the mosque was renamed and the apse was added.
The edifice was then known as Mezquita Bab-al-Mardum, deriving its name from the city gate Bab al-Mardum.
Built in 999 in Toledo, this building is a rarity in that it is in much the same state as it was when it was originally built. The building is a small square structure. It measures roughly 8 m × 8 m. Four columns capped with Visigothic capitals divide the interior into nine compartments. Covering each of these bays is a vault that has a distinctive design that is unique unto itself. The central vault is higher than the other ones and acts as a cupola for the structure. Each vault employs the use of ribs to create the designs that make them unique. Each of them follows the basic ideas of Islamic design. The ribs typically do not cross in the center, an idea that is seen in many Muslim designs. Some of the designs are more rectilinear while others embrace the curved forms of the vault more prominently. Within each one is a piece of their culture and tradition of building. The columns and the capitals both had been taken from previous buildings and are therefore known as spolia.
The building is constructed of brick and small stones. These techniques are a reflection of both the local building tradition as well as the influence from the caliphate in Córdoba. The influence of the caliphate can be seen in the brickwork on the facade of the building which resembles those seen at the Cathedral–Mosque of Córdoba. Originally the Eastern wall was a continuous stretch of brick and served as the qibla wall for the mosque. Also located along this side would have been a mihrab used for worship. The other three facades are articulated by three-bay arcades. All are similar, but individual in their decoration.
The Western wall which served as the main entrance is unique in how the arcade is articulated. This facade has a lobed arch, horseshoe arch, and a wider version of a horseshoe arch. Brickwork arches provide the decoration for the facade which are influenced by the architecture in Córdoba. In later years a Mudejar semi-circular apse was added. In the process of the addition the qibla wall and mihrab were lost. The use of the mudejar style provided a smooth transition from the original structure to the apse, as the addition uses the same style of decoration and materials as the original. The continuation of the arch motif is an important link between the two sections of the building.
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.