Even if you wait until the very last minute to book a long weekend getaway, you can still be sipping on piña coladas on a beautiful beach in no time. Kayak found that the median airfare of a flight to Puerto Rico when booked the week of Labor Day is still well under the $300 mark. And with oceanside suites renting for as little as $55 per night on Airbnb, your dreamy late Summer escape won't make a huge dent in your wallet, either. Get ready for three days of exploring mountains, waterfalls, and dense rainforests — or if you'd rather spend all weekend basking in the sun, there's no shame in that, either.