As the school year comes to a close and graduation ceremonies wind down, many high school and college graduates embark on the cultural phenomenon known as the gap year. For young adults craving a gap year adventure before entering the workforce, and for travelers of all ages planning to travel abroad, not all destination cities are created equal.

For gap year travel, and any long-term trips, travelers must factor in cost-of-living more so than travelers visiting for shorter periods. Factors like the exchange rate, cost of food, and cost of public transportation become even more important than the cost of international airfare. While many European cities are notoriously expensive, there are many top international destinations with surprisingly cheap day-to-day costs. For gap year travel that won't wipe out your budget, consider heading to one of these surprisingly cheap international destinations.

Istanbul, Turkey

As one of Europe's up-and-coming hotspots, perhaps the most attractive thing about Istanbul is its relative unpopularity with U.S. tourists. Travelers should take advantage Istanbul before the masses catch on and prices skyrocket. This busy and vibrant city has everything an international traveler could want: breathtaking architecture, important historical sites, busy marketplaces, and world-class dining and nightlife.

Kuala Lumpur, Malaysia

A recent boom in Kuala Lumpur's economy means that the bustling city is teeming with tourism attractions, but still dramatically more affordable than traditional international travel favorites. Savings on travel costs will add up quickly in Kuala Lumpur, from low price fine dining, to low cost luxury hotel accommodations and inexpensive cab fares. The city will leave even the most distinguished international traveler fulfilled, with museums, shopping, beaches, and jungles to marvel at.

Lisbon, Portugal

Lisbon boasts the striking cathedrals, monasteries, and museums that travelers expect of prime European locations, but for a much lower price tag. Travelers cut costs in many ways, with cheap authentic Portuguese food abundant in small taverns and affordable nightlife in the areas surrounding universities. Head to museums on a Sunday: many of them are free for one day only.

Buenos Aires, Argentina

Buenos Aires is one of the top value international destinations in the world. Lodging accommodations, dining, and shopping are all shockingly affordable in Argentina. Enjoy the vibrant street life of El Puerto de Buenos Aires, witness the country's signature dance, the tango, and make sure to witness a soccer game, all without breaking the bank.