Pool hangouts and parties

While they've always been a prominent feature for hotels, the importance of a great pool scene has skyrocketed over the last few years, thanks almost entirely the exploding popularity of daytime pool parties during the warm months. The Hard Rock's "Rehab" led the way, but now it's rare to find a major hotel that doesn't have some kind of gala happening at their pool.

The "IT" party may change from season to season, so check with your concierge -- or just a friendly bartender -- after you arrive if you want to make sure you hit the hippest of the hip parties. There's no such thing as a lame Vegas pool party, though, so rest easy knowing that wherever you go you'll see something worth telling friends about.

Here are a few basics about Vegas pool life that you should know:

Pool season

Most major hotels have at least one pool that is open year round, but there's a big difference between being "technically open" (meaning you're welcome to walk around and look at a deserted pool while the temperature is too cool to think about jumping in) and being "really open." Dates for "really open" vary a bit, but usually you can count on open pools from March through October.

Pool admission is usually free only to hotel guests

First of all, not every hotel pool allows non-guests to enter at all. Those that do won't let you in for free. Costs vary depending on day of the week and other factors, but a good estimate is to expect entry fees in the range of $10 for women and $20 for men; oftentimes double that rate on weekends. Yes, dudes have to pay more than chicks. Get used to that, because it happens a lot.

Rules are different for pool parties

Even if a pool doesn't normally allow public entry, they will for their scheduled pool parties. Don't expect it to be cheap. While hotel guests sometimes still get free entrance, everybody else pays to get into the party. And pays a lot. Guys should expect entry fees to start at around $40 and go up from there. As always, women will get in for about half that cost.

You get no break on prices once inside

When they're not having a party hotels don't usually jack up drink prices very much, if at all. But during a party... well, if you find yourself paying $20 for a drink don't be surprised. If it's any consolation, at least it will be a huge drink.

If you're under 21, don't bother trying

Those of less than legal age can enter most pools most times, but nobody underage is getting into one of the pool parties. This is a rule the hotels enforce very strictly. At least they have since Paris Hilton turned 21.

Boobs in the breeze

Yes, there are pools with "European bathing" areas, meaning tops are optional for the ladies. Yes, the scenery is often spectacular. And, yes, guys you'll usually have to pay to enter, even if you're a hotel guest.

If you don't like kids, stay away from these

The pools at Circus Circus and Excalibur are often flooded with children. If you're looking for a wild hookup scene or a quiet, relaxing spot to soak up some UV and read a good book, these two pools aren't for you at all.