The so-called Astronomical Bastion was part of the Königsberg fortification system. It was built between 1855-1860. The name was inherited from the adjacent observatory built by F. Bessil in the 1813. After the construction of the railway station in the 1910, the part of the bastion was destroyed.
References:House of the Blackheads (Melngalvju nams) is a building situated in the old town of Riga. The original building was erected during the first third of the 14th century for the Brotherhood of Blackheads, a guild for unmarried German merchants in Riga. Major works were done in the years 1580 and 1886, adding most of the ornaments.
The structure was bombed to a ruin by the Germans June 28, 1941 and the remains demolished by the Soviets in 1948. The current reconstruction was erected from 1995 to 1999. Today the House of Blackheads serves as a museum and sometimes concert hall.