during the Soviet era. Geology The town is located on the Neva Lowland, to the left of the river Neva, in the valley of the Slavyanka River. The landscape is quite varied and contains hills, ridges and terraces intermixed with valleys, plains, forests and farmland. Numerous springs give rise to streams and feed ponds. In the Paleozoic era, 300–400 million years ago, the area was covered by a sea. Sediments of that time form a layer thicker than 200 meters on top of the Baltic Shield consisting of granite, gneiss and diabase. The modern topography was shaped by the glacier retreat some 12,000 years ago which created the Littorina Sea. About 4,000 years ago the sea receded and formed the valley of the Neva River which has not changed much over the last 2,500 years. Climate The climate of Pavlovsk is temperate and wet, it has a continental climate. The length of the day varies from 5 hours and 51 minutes in the winter solstice to 18 hours and 50 minutes in the summer solstice. Summer is short and moderately warm, whereas winter is long and uneven, with frequent thaws. Air temperatures above prevail from early April to mid-November. The coldest month is February. Winds mostly blow southward and frequently change air mass above the city. Summer is dominated by westerly and northwesterly winds, and the wind direction changes to westerly and southwesterly in winter. The cloudiest months are November, December and January, and the least cloudy are May, June and July. There are at least 240 sunny days per year. Between May 25 and July 16, white nights are observed when the sun only briefly goes over the horizon and the day lasts nearly nineteen hours. The area is mostly fed by surface and ground waters. Soil, vegetation and wildlife Prior to the founding of the town the area was covered by temperate coniferous forests (mostly pine and fir) with an admixture of broad-leaved trees and fens. The soils were mostly podzol, combined with peat and gleysols. Intensive economic activities changed the original forest landscape to agricultural land with small groves of aspen, birch, alder and willow. In the 18–19th centuries, a large park area of almost 600 hectares (Pavlovsk and Arensky parks) has been created in and around the city. Owing to the parks and environment-friendly policies, the Pavlovsk area has relatively low level of pollution. In 1978–1983