The owner of The Royal Victoria hotel in Llanberis, Gwynedd, Coronet Holidays, is to add a luxury spa to the venue.
The company is planning the rear extension on the Snowdonia Grade II-listed hotel in order to attract additional visitors.
Initial proposals for the scheme have been drawn up, and Coronet aims to seek advice from planners before making a formal planning application.
The spa area would include treatment rooms, a sauna, steam room and spa pool.
The 104-room hotel dates back nearly 200 years and is set in 30 acres of gardens and woodland.
Coronet has already invested significantly in the site and plan other upgrades to the entrance area.