The impressive pilgrimage church of St. Oswald in the village centre of Seefeld was first mentioned in historical documents in 1263. After the legendary "Hostienwunder" of 1384, it became one of the most famous pilgrimage sites in Tyrol: According to legend, Oswald Milser is said to have demanded a larger host (blessed wafer) from the Grenzfeste Schlossberg at the Holy Mass than for the "common leader". The host, willingly handed over by the priest, turned blood-red and the stone on which he knelt, as well as the heavy altar stone, sank abruptly into the ground. The imprint of the hand, which still desperately wanted to hold on to the stone slab of the church altar, is clearly visible there to this day.

Due to the large influx of pilgrims, the church was extended with the empty bag in 1425 on behalf of Duke Friedrich and completed in 1474 under "Sigismund der Münzreiche". Emperor Karl IV adapted the Renaissance design of the adjoining "Blood Chapel" (where the Wunderhostie was kept) with elaborate stucco work and an original Puellacher ceiling fresco to the taste of Baroque art.

Today the pilgrimage church of St. Oswald is one of the most beautiful late Gothic buildings in Tyrol.