We don’t generally write directly about businesses here, but we are making an exception for Maruia Springs because it is exceptional and a good base if you want to explore the area around Lewis Pass for more than a day.
There is both camping and private room accommodation, with a spa, luxurious hot springs and a superb restaurant. We even drove back there for dinner after hiking around Reefton.
The location is a few kms after Lewis Pass (west side) and in the Maruia River Valley. They also have their own descriptions of the various nearby hiking options, including one you won’t find on the map.