How we research and rank

Every hotel on this site has a pool on its roof that we could confirm from the hotel's own pages. Here is exactly how we get there, and what we do when the facts run out.

1. What counts as a rooftop pool

A swimming pool on the roof or the top level of the building, open to swim in. We leave out hot tubs and spa plunge baths on their own, terrace pools on a low floor of a tall building, and rooftop bars with no pool. Each city page lists the hotels people expect to see that didn't qualify, with the reason: 724 of them across the site.

2. Where the facts come from

For each city we start from the hotels that search results, guides and booking sites say have a rooftop pool. Then, for each hotel, we read:

• the hotel's own website (pool, rooftop, FAQ and amenities pages);
• its Google listing, for the address, phone, rating and map;
• the day-pass seller's page for that hotel, for the price of a pass and the date we read it.

Every fact is stored with the page it came from and the words that support it. The hotel's own pages win any conflict. A fact that only a travel guide, blog or booking site gives is shown as unconfirmed, and we keep it out of our written verdicts.

3. What we check for every pool

Who can swim (guests only, or non-guests with a day pass), which floor the pool is on, the pool type and size, whether it's heated, the season and hours, age rules, the day-pass price and what it includes, and whether the rooftop bar is open to the public. Where a hotel doesn't publish one of these, the page says "not published" rather than guessing.

4. How we rank hotels in a city

The order on each city page favours the pool a visitor can most easily use and rely on. In order of weight:

1. Access. Pools that non-guests can use, especially with a day pass sold online, rank higher.
2. Guest ratings. The hotel's Google rating, weighted by the number of reviews so a handful of five-star reviews doesn't outrank thousands of good ones.
3. Published facts. Hotels that publish their pool's floor, hours, season, heating and access rules rank above those that publish none, because you can plan around them.
4. The hotel and the height. Hotel class and the floor of the pool break close calls.

Commission plays no part in the order: every hotel links to the same booking site, and hotels can't pay to move up.

5. What we haven't done

We haven't swum in these pools, and we don't pretend to. Our verdicts compare what the hotels publish and tell you who each pool suits. Ratings come from Google and cover the whole hotel, not just the pool.

6. Keeping it current

Each city page and hotel guide shows the date its facts were checked. We recheck cities before their swim season, and immediately when a reader reports a change. Report a change.

The site currently covers 790 hotels in 93 cities. We add a city once at least three of its hotels have a confirmed rooftop pool.