At this stage I don’t know if Groupon deal will be extended beyond the expiry date of 31st May. That means you should travel before this date. However, what I can suggest you, is to book this tour directly on our website. See the link below:
Please notice that this tour is already discounted, regular price is 91 GBP. Also, please note that entry to Roman Baths is included, which is not part of Groupon deal.