The so-called Powder Tower originally served as one of the Riga defensive system buildings. There is no information on the exact date of the construction, but the first tower on this place was built in the 13th century. The name of a tower - Powder, has appeared later. In documents for the first time this place has been mentioned in 14th century by the name of Sand tower. The modern tower has been constructed on a boundary of 15th and 16th centuries. During the centuries it has been collapsed and later restored. The entrance of the tower was at the height of 5 meters, and it was possible to get to a tower only having walked upstairs.
After the Great Northern War the Powder Tower lost its military value. Tower reconstruction was began in the end of 19th century. The new pointed roof has been constructed. Last time the tower has endured reconstruction after the First World War when the Military museum of Latvia has been situated in it.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.