The Cenas tīrelis is a bog located in the municipalities of Mārupe and Olaine, approximately 30 kilometers west of Riga, Latvia.

[3] The bog has a total size of 6,000 ha,[4] mostly occupied by the nature reserve and an active peat extraction site.

The Cenas tirelis bog is the second largest peatland in Latvia, after the Teiči Nature Reserve, which has a total size of 19,779 ha.

On the widest point away from the start, close to an old military road from WW1, a bird watching tower and picnic tables can be found.

Along the way, several information boards explain about the resident flora and fauna as well as about the peat industry in Latvia and the world in Latvian and English language.