Sirtsi peatland is located in the northwestern part of Ida-Viru County, 7.5 km south of Sonda, in an ice lake depression. The south-western border is the Rakvere-Mustvee road, the south-eastern edge is crossed by the former Sonda-Mustvee railway. The peatland  formed by terrestrialisation . It feeds on precipitation, also by sand and moraine water. The Hirmuse and Purtse rivers are water recipient.  A spruce-birch woodland spreads in the fen areas , transitional bog woodland is pine-birch forest. A wooded bog spreads on the outskirts of the bog, in the middle there is often an impenetrable bog with bog pools  and hollow-ridges ; Sirtsi is rich in cranberries and cloudberries. The area of ​​the peatland is 5644 ha. It is partly located in the Sirts Nature Reserve with a total area of ​​4,525 ha, which includes the entire deeper peatland. Peat reserves are calculated on 3246 ha. There are 2375 ha of fen deposit, 650 ha of mesotrophic peat deposit, 472 ha of mixed- bog deposit, 2147 ha of bog deposit (Orru et al., 1992). The passive reserve  in the peatland, which is slightly decomposed, is 4.55 million tons. Average thickness is  2.62 m and max 3.75 m. Decomposition is 12%, natural moisture content is 94% and ash content is 1.7%. The passive reserve of the well-decomposed peat in the bog deposit is 4.84 million tons. Average thickness  of the peat is1.1 m and max 2.4 m. Degree of decomposition is  24%, ash content  is 2.4% and natural moisture content is 93%. The passive reserve  of the  well-decomposed  fen deposit  is 0.15 million tons. Average thickness 0.9 and max 0.9 m. Decomposition is 35%, 90% is natural moisture  and ash content is 3.4%. The passive reserve of the well-decomposed peat of the mixed-bog deposit is 1.44 million tons. The average thickness is 2.13 m and 5.4 m is max. Decomposition rate is 25%, natural moisture content is 93% and ash content is 2.6%. The passive reserve of  the well-decomposed fen  peat is 1.44 million tons. The average thickness of 1.27 m and 1.75 m is max. Decomposition is 35%, natural moisture content is 93% and ash content is 2.7%. The fen deposit is very limited in the south-eastern part of the peatland, where it consists of well-decomposed (40%) wood peat. The thickness of the deposit is 1.2 ... 2.3 m, ash content is 3.4%, moisture content is 91%. The transitional deposit spreads all over the periphery of the bog and consists of moderately decomposed (35%) sedge  and reed peat. The thickness of the peat deposit is 1.30 ... 2.60 m, ash content is 3.2%,  moisture content  is 93%. The mixed- bog layers occurs as small areas in the margins of the bog and in the south-eastern part between the two bog areas. The upper part of the deposit consists of cotton-grass -Sphagnum peat, the lower layers  of the deposit there are Sphagnum peat and the reed peat, the degree of decomposition is 25%. Peat thickness is 2.1 ... 5.4 m, ash content is 2.1%, moisture content is 93%. The bog deposit covers most of the bog, especially its deeper part, and consists of  Sphagnum, southern S. fuscum,S. medium  peat. The thickness of the deposit is 3.5 ... 6.0 m, moisture content is 94%, ash content is 1.2%. The thickness of the slightly decomposed peat layer is 2.6 ... 3.7 m (Orru et al., 1975). The reserve is all passive reserve , including 4.55 million tons of slightly decomposd peat and 7.88 million tons of well-decomposed peat. Sirtsi peatland have not been drained. The bog remains in its natural state, as it is mainly located in the bog protection area. Berry-rich (blackberry, cranberry) and  hollow-ridge bogs need to be preserved. The area of ​​the abandoned peat production area is 32.12 ha.