The esker of Vahteristonmäki, reaching past lake Kymijärvi further north into Heinola, peaks at 177 metres (581 ft) above sea level in Nastola.

[7] Till is the dominant type of soil in central and northern Nastola, with clay deposits mostly being concentrated to the south of the first Salpausselkä, as well as around the lakes of Ruuhijärvi, Sylvöjärvi and Oksjärvi.

The rocks on the south side of the Salpausselkäs tend to be lower and more rounded, and the majority of the bedrock consists of granite.

All of the lakes of Nastola, which are also all part of the Kymijärvi drainage basin, are situated to the north of the first Salpausselkä; to its south are several smaller streams of water.

[7] Arrajoki, Immilä, Koiskala, Lankila, Pyhäntaka, Ruuhijärvi, Uusikylä, Vanaja, Villähde, Kirkonkylä, Rakokivi, Seesta- Luhtaanmaa, Järvinen, Tapiola.