British explorer Dame Freya Stark once said, "To awaken quite alone in a strange town is one of the pleasantest sensations in the world." We think this late adventurer was on to something: Traveling on your own can be invigorating. While roaming solo, your senses will thrill at unfamiliar sights, sounds, and tastes; interesting strangers will upend your preconceived notions; exciting adventures will lie at every turn.But you need to know the places to go. After all, Paris—with its profusion of honeymooners—might make you pine for that one who got away, and Juarez (with its high crime rate) might make you fear for your life. However, lively cities like Dublin and Nashville offer visitors an ideal combination of safety, friendliness, accessibility, and affordability. With these qualities in mind, U.S. News Travel has compiled a list of the best cities to explore solo.Chi-town is an exciting metropolis with a down-to-earth Midwestern mentality. In a sense, you get the big-city buzz of Manhattan with the neighborliness of Missouri. And as far as major cities go, Chicago is very safe and its public transportation system is user-friendly. When it comes to cost, the Windy City does have options that could tempt you to part with your cash. But there are affordable options, too. For instance, window-shopping along the Magnificent Mile is free, as is wandering through Millennium Park.Best Activities for the Solo Traveler: Spend your morning in the Field Museum or the Art Institute of Chicago before digging into a slice of deep dish at one of the city's many pizzerias. Later, rent a bike and cycle up to 18 miles along Chicago's picturesque lakefront.Dublin belongs to a country known for its "thousand welcomes." In other words, natives of the Emerald Isle are very amenable to travelers. Pop into any one of the city's pubs (except during St. Patrick's Day, when the watering holes fill with foreigners), and most of its guests will be more than happy to share a pint and some conversation. Plus, Dublin is relatively affordable, despite the exchange rate. And since there are nonstop flights from the United States to Dublin International Airport, getting there is a cinch, too.Best Activities for the Solo Traveler: If you're looking to drop some dough, head to Grafton Street for your pick of everything from shoes to books. Later, take a literary tour and stop at a pub for a Guinness and some fish and chips.To say that New Orleans is a friendly city would be an understatement: This storied city loves its out-of-towners. After all, Americans throughout the country flocked to the city to clean up after Hurricane Katrina. And let's be honest, Mardi Gras just wouldn't reach its full potential year after year without an influx of visitors seeking debauchery. Although tourist areas like the French Quarter and the Garden District are pretty safe, you should observe caution in some of New Orleans' other neighborhoods.Best Activities for the Solo Travel: Enjoy a beignet (and the subsequent sugar rush) from Café du Monde, and take a coffee to go as you wander the French Quarter. Later, carve out some time for meandering through the city's many cemeteries. In the evening, enjoy some Cajun cuisine at Acme Oyster House and live Zydeco music and bowling at Rock 'n' Bowl.Home to Taylor Swift, Brad Paisley, Keith Urban, and many more iconic musicians, Nashville is the place to get your country-music fix. But besides the Grand Ole Opry, where the legends take to the stage, and the Country Music Hall of Fame, where more legends are enshrined, you might wonder what else there is to see. Every night, hopeful artists play original music in the city's bars, and nearly every day, it seems a new trendy boutique or restaurant is opening. You can experience all of this crackling creativity, while at the same time resting assured that Nashvillians will treat you as one of their own: Southern hospitality is practically an art here.Best Activities for the Solo Traveler: Grab a burger and share a table with strangers at The Pharmacy Burger Parlor & Beer Garden, browse titles at the independent Parnassus Books, shop the boutiques of Hillsboro Village, and tap your foot to some bluegrass at the Station Inn.One of the Texas capital's more interesting slogans is "Keep Austin Weird." When a city touts its "weirdness" as one of its most admirable qualities, you know it's going to show you a good time. This quirky city is also the self-proclaimed "Live Music Capital of the World." Take that as you will, but you'll find evidence of this hyperbole all throughout Austin, especially in the melodies that pour from 6th Street's bars. This sunny city is also pretty cheap: Forbes listed it as the 12th most affordable place to live in the United States this year. Best Activities for the Solo Traveler: After grabbing a bite at Franklin Barbecue, head over to Zilker Park. Later, check out the bats under the Congress Avenue Bridge before snagging a beer and some live music along 6th Street.This harborside city may cost a pretty penny to reach, but it's worth the splurge. First off, Aussies regularly travel by themselves, so they won't miss a beat to see you doing the same. Plentiful hostels offer travelers cheap accommodation, as well as a forum to meet other visitors, and many of the city's top attractions won't cost you a dime. For instance, activities such as hiking through Sydney Harbour National Park, swimming at Coogee Beach, and people-watching in Sydney Harbour are absolutely free. Lastly, locals are known for their laid-back way of life, so even though Sydney is a major metropolis, it's easy to unwind and self-reflect here.Best Activities for the Solo Traveler: Start your day by soaking up the sun and surf at Bondi Beach. Then, pick up some gelato from the nearby Pompei's Gelateria. Fill the afternoon hours at a museum or two, then close out your day at The Rocks.If you want to get closer to the equator, you could visit Mexico. But if you're already headed south, why not travel a little farther to Costa Rica? This Central American country is known for its lush jungles, picturesque beaches, and exotic wildlife. Here, you can lounge on Nicoya Peninsula's powdery sands, hike the fiery Arenal Volcano, or explore the capital, San José. Plus, accommodations are very affordable, much more so than hotels found at popular destinations in the Caribbean and Mexico.Best Activities for the Solo Traveler: Find a spot along the Nicoya Peninsula's 80-mile shoreline to soak up the rays. To meet fellow travelers, book a guided tour in one of the country's national parks or through its beautiful coffee plantations. Then, head to San José and pick up a souvenir or two on Avenida Central.