Boldog Özséb Observation Tower, Observation tower in Pilisszentkereszt, Hungary

The Boldog Özséb Tower is a wooden observation tower in Pilisszentkereszt that rises to 17.25 meters at an elevation of about 756 meters on Pilis-tető mountain. The structure provides an elevated viewing platform with open sightlines across the surrounding landscape.

A cylindrical geodetic measuring tower was built on the summit in the 1970s. In the early 1980s the area became a military zone hosting the 11/2nd home air defence missile division (MN 1059) with SZ-75 missiles; the base was disbanded in 1995. The tower was rebuilt into a lookout between June and October 2014 by Pilisi Parkerdő Zrt., keeping and raising the concrete walls.

The tower is named after Boldog Özséb (Blessed Eusebius), founder of the Pálos order, who according to tradition lived as a hermit in this region. The name ties the summit to the order's origins; Pálos and Cistercian monastery ruins lie nearby, at Pilisszentlélek, Klastrompuszta and Pilisszentkereszt.

The tower can only be reached on foot, on marked hiking trails. The shortest route starts at the Orosdy-kastély above Pilisszántó and climbs steeply almost straight to the summit. The gentlest approach is from the Két-bükkfa-nyereg saddle near the Pest–Komárom-Esztergom county border, where a marked trail and a forestry road (closed to public traffic) lead up.

The tower's concrete core is the original 3.5-metre-wide, 12.5-metre geodetic tower from the 1970s, raised by 4.75 metres in 2014. Its outer skin of 10×15 cm pine beams hides a spiral staircase inside the core, keeping the meteorological station's instruments separate from visitors.