Natural Features and Settlement-Geographic Characteristics of Eger Eger is situated at the northeastern part of present-day Hungary, in a hilly area between the Northern Mountain Range and the Great Plain region, in the valley of the Eger stream. The average altitude of the historic town is 140-160 m, while the castle and the more recent areas were built on terraces at 160-200 m above sea level. This basin is surrounded by a 220-300 metre-high hill range from the East and the West. The geology in and around Eger is very versatile, with sedimentary and also volcanic rocks. The 12km-long valley has a moderately warm and moderately dry climate, with a 9.9 °C annual mean temperature and a 16.9 °C long-term mean temperature during vegetation periods. The frostless period is more than 185 days, exceeding 190 days on the southern slopes. The rainfall averaged 590 mm over the last 125 years (1871–1995), with 355 mm during the vegetation period. The Eger stream flowing across the town has a low watermark for most of the year, but its discharge multiplies during floods: substantial floods are usually not due to snow floods, but to summer storms. Several devastating floods have been recorded during the history of Eger. Eger has a large supply of thermal water and medicinal springs, which flow from cracked, karstified carbonate rocks. Thermal water and warm water lakes have been used by the town’s inhabitants as early as the middle ages, with records about bathhouses from the late 16th century. Among the settlement-geographic factors, the characteristics of the terrain played an important role in the development of the town. The first settlement was created on the castle hill. This is the narrowest section of the Eger valley, therefore, for defence purposes, provided the best location for the Episcopal seat and later, the fortress. Although this area was excellent for defences, it was unfavourable for town development. Since the town could not be extended to the east, only the narrow valley between the castle hill and the stream was suitable for new settlements. The growing community populated the western side of the stream. The flow of the stream and the watercourse from the hillsides limited the area for smaller districts, and determined the development of housing areas built in rows or random structures. The town was actually created by merging these separate islands of settlement.