The protected nature park Terčino Údolí (Theresa's Valley - 140 ha) lies 1 km south-west of the town Nové Hrady in the valley of the small river called Stropnice in the Novohradské Hory (Nové Hrady Mountains).
The park was established by Jan Buquoy according to wishes of his wife Tereza (Theresa) in the second half of the 18th century. The park was reconstructed at the turn of the 19th century and many exotic woods were planted here and most of the spa houses were built here at that time. The oldest building originates from the end of the 18th century and the so-called "Blue House" was built at the beginning of the 19th century. The main building of the spa and the "Swiss House" were built in Art Nouveau style in the 19th century. The former iron-mill from the end of the 18th century and the man-made waterfall on the Stropnice river can be seen in the valley as well. Near the eastern border of the park there is the very well preserved Gothic Cuknštejn fortress from the end of the 15th century.
The park has been protected since 1949.
Now it is a recreation area. The circular path passes through the whole park.
Also two circular instructional trails (Terčino Údolí and forester instructional trail) lead in the park.
The central gate to the valley is in the village Údolí below Nové Hrady in the direction of the village Horní Stropnice