ARCHAEOLOGICAL EXPLORATIONS IN PLISKA (Pavel Georgiev – pavel_g@gbg.bg, Gergana Ilieva) The area to the west of the entrance of the Great Basilica was explored. A pavement of stone slabs was discovered. It covered a square situated in front of the basilica. Several places for mortar stirring were documented. The area was a construction site before the pavement was placed. A drain, which collected the water from the roofing of the atrium, was discovered. The drain was without bottom (absorbing), while its sides were constructed of stone slabs and it was covered with slabs. Three parallel stripes of mortar fragments were discovered. The stripes are 80 cm wide, up to 6.70 m long and 55 – 70 cm thick. Most probably these are the beds of foundations, which were filled with mortar fragments. A pit, 2.20 m deep, was discovered in the central apse, behind the preserved part of the synthrone. The pit contained fragmentary bricks and mortar, charcoal and iron slag. Evidently, it was dug before the construction of the basilica.