Pent-up demand for travel nearly 15 months into the COVID-19 pandemic has set the stage for a surge of long-awaited summer vacations in 2021. However, traveling somewhere new and exciting without the worry of coronavirus testing or vaccination requirements doesn't have to blow up your budget if you know where to go. Here are some of the most wallet-friendly U.S. cities you can visit with ease this summer.

Buffalo is an underrated American city that offers summer travelers plenty of wallet-friendly surprises just a short distance from iconic Niagara Falls. The city ranks second nationwide for travel costs and hassles and 12th for local costs this summer, based on recent research from WalletHub. Not only is this as close as Americans can get to Canada at the moment, but there's plenty to see and do along the waterfront as well as lots of art and museums to explore.

The Steel City boasts plenty of free or affordable things to do so travelers can stretch their budget further this summer. Taking in the epic view from Mount Washington, touring the Frick Art Museum (admission is free) and checking out the oldest remaining structure in Pittsburgh in the Fort Pitt Blockhouse at Point State Park at the famous confluence are just a few of the exciting and free activities that await.

Oklahoma City is the ninth-best summer travel destination in the U.S. for 2021, according to WalletHub, ranking second among the nation's 100 largest metro areas in terms of local costs and a solid 25th for travel costs. The former category takes into account the cost of living as well as the lowest nightly rate for a three-star hotel room and the average price of a two-person meal. Touring the newly-renovated Oklahoma City National Memorial Museum will cost you about as much as a movie ticket but that's hardly all there is to do for cheap in the "Horse Show Capital of the World."

For travelers who don't mind Phoenix's scorching summers, the Valley of the Sun offers plenty of exciting experiences that won't break the bank, including air-conditioned fun at the city's many museums on free admission days. And while visitors will also find plenty of entertainment and comfort checking out Phoenix's restaurants and nightlife, the outdoor adventures stand out here as hikers, runners and mountain bikers have no shortage of awesome trails to explore featuring amazing views and even ancient petroglyphs.

The Theme Park Capital of the World will not be without crowds this summer as it remains one of the most popular vacation spots in America, especially among families. However, it ranks as the number one summer travel destination for 2021, based on WalletHub's research. Orlando ranks first for activities, second for attractions, third for local costs and 24th for travel costs and hassles, which considers flight costs, connection options and rate of delays.

Indianapolis is another budget-friendly travel destination for summer vacationers in the Midwest, offering well over 200 city parks, an eight-mile-long cultural trail, numerous Instagrammable murals, free admission days at top museums and attractions, the can't-miss Monument Circle and exciting family-friendly events at White River State Park.

Located on the doorstep of the Great Smoky Mountains in eastern Tennessee between Nashville and Charlotte, Knoxville ranks fourth nationwide in terms of the lowest local costs, according to WalletHub. In addition to affordable hotel stays and budget-friendly activities, travelers can look forward to a variety of free experiences, including the Ijams Nature Center, several art museums and galleries and inviting botanical gardens and farmers' markets.

Summer visitors to Milwaukee certainly won't want to miss out on the city's mouthwatering brewing companies and beer gardens but you'll still have plenty of free or cheap options if you're worried about running up your tab, including scenic lakefront trails, eye-popping street art and live music. Even the city's marquee attractions such as the Harley-Davidson Museum can be accessed for relatively cheap ($22 for adults).

About two and a half hours north of Oklahoma City is where you'll find Wichita, a city that ranks seventh nationwide in terms of local costs and 12th for travel costs, based on WalletHub's latest research. The famous 44-foot-tall Keeper of the Plains sculpture is completely free to visit, of course, and the Wichita Art Museum is free on Saturdays. Visitors can also stretch their budget by opting for any one of the city's dozens of parks and trails, which include a focus on art, history and culture. Summertime visitors will also enjoy Wichita's fountains and splash parks.

Albuquerque ranks sixth in the country in terms of local costs, according to WalletHub, and will be a welcome summer escape for those eyeing a hot and dry visit. Road tripping iconic Route 66 is one of the best ways to experience this city, which is an absolute must for travelers captivated by art, history and culture. Albuquerque features tons of museums and monuments and the destination's many events and performances won't cost visitors a dime to experience.

Located just over the Georgia-South Carolina border and most famous for hosting golf's annual Masters Tournament, Augusta is the eighth-best destination in America for local costs this summer and is no stranger to budget-friendly experiences, including socially distant outdoor activities ideal for the summer season. The Augusta Riverwalk and Canal are no-brainers for first-time visitors while Phinizy Swamp Nature Park is the perfect trip for wildlife enthusiasts hoping to spot herons, hawks, otters and more. If you're looking for more charm without the cost, head west to Athens. Or, for a big city experience, keep driving to Atlanta, which is also relatively wallet-friendly compared to America's leading cities.

In a state the size of Texas, San Antonio doesn't always get the love it deserves. Nonetheless, it won't take budget-conscious visitors long to fall head over heels for the Alamo City and nearby New Braunfels, which WalletHub ranks 13th for summer travel in 2021. After all, the region is the nation's 11th-best for travel costs and ranks 27th for local costs this year. The Alamo, missions and riverwalk are not to be missed but travelers will have lots more to explore this time of year, including some overlooked but exceptional theme parks in Six Flags Fiesta Texas and Schlitterbahn Waterpark.