Before the year 850 AD there is already a small church here at this very isolated location outside the settlement at the mouth of the Lahn. In about 1130 it is replaced by today’s Romanesque pillared basilica. Today it is the oldest surviving galleried church on the Middle Rhine.
This is a very special location for a church, for at the time of its construction there is an island at this point which separates two arms of the Lahn estuary. Over the years the watch-tower or Burgus which the Romans once built here had fallen into ruin. Now it is the church, a symbol of faith, that dominates the scene on the island. It becomes Niederlahnstein’s landmark and later becomes a popular motif of Rhine Romanticism.
After the church is ravaged in the 30 Years’ War, it is rebuilt in the Baroque style. The wars of the French Revolution turn it into a burnt-out ruin once more. In the year 1856 work begins on the reconstruction of St. John’s Church. At the beginning of the 20th century a monastery with inner courtyard is added on the north side.
The six-storey west tower of St. John’s Basilica is particularly notable. The lower floors originate from an earlier church which stood here in about the year 1000. The top floor dating from the year 1136 is original and is one of the oldest tower roofs in Germany. The 34 m high tower also contains Lahnstein’s oldest bell, to which the bells of all Lahnstein’s churches are
tuned. The overall plan for the church included another two slimmer towers. One of them, the so-called Horchheim Tower, was built in the year 1180 but collapsed in 1844. There is no documentary evidence for the construction of the second tower.
The patron of the church is St. John the Baptist whose Baroque figure can be seen inside the church underneath the organ railing. The Madonna with the Pearl Turban from about 1480 is of particular art-historical interest.