Activities15th “ASTROPARTY BAYCAL”2019on 06/03/201910/30/2022 From 31 May to 01 June 2019, the 15th “ASTROPARTY BAYCAL” 2019, on the bank of the Dunav river in the village of Baikal, Dolna Mitropoliya Municipality. an astro-workshop “Mathematics and astronomy”.