Sounds like you have a business that is well positioned in the current market and the idea of a cleaning service does provide some diversification as well as additional turnover, not to mention spreading your risk.
My opinion is that it is not a great time to sell tourism or visitor related businesses at the moment and that you might find that there is plenty of opportunity in the current state of the industry for expansion and growth as you have suggested.
Value of a business is linked to a number of factors such as the future earning capacity of the business, its trading environment, the market view in the medium term etc. I would recommend that you dedicate time and resource on some sound advice in this area before taking the decision to sell.
Hope this is of assistance and all the best.