Jelení hora, Mountain summit in northern Bohemia, Czech Republic.

Hassberg (Czech: Jelení hora) is a 993 m nefelinite hill in the Ore Mountains, the highest point of the Přísečnická hornatina. Its summit is a slightly sloping lava plateau with steep slopes, and a concrete-clad stone pillar marks the geodetic point at 993.71 m. About 250 m northwest of the top, six-sided nefelinite columns up to 30 cm wide and 4–5 m high tilt 45° to the southeast.

Countess Gabriela Buquoy had a wooden viewing hut with a rooftop platform and a stair built on the summit in the 1830s; it was renewed in 1852 and demolished at the end of the 1880s. A report of 1924 mentions a wooden pyramid on the highest point, and in 1928 an 18-metre observation pyramid was erected there. A castle, the Haßburg, is said to have stood on the mountain and has completely vanished.

The Czech name Jelení hora means "Deer Mountain", while the German name Hassberg refers to a castle, the Haßburg, that is said to have stood on the slope and has completely disappeared. The yellow-marked trail from the red Nová Ves–Měděnec route leads directly to the summit.

The summit is reachable via marked forest trails with the main route starting from nearby villages. Good footwear and basic navigation skills are helpful for a safe visit.

The summit's 994 m figure refers to a concrete-clad stone survey pillar standing well above the ground; the actual summit plateau is 993 m. The column marks a geodetic point on the flattened top of a Tertiary nephelinite lava flow.