The view from the Griffith Observatory in Los Angeles. Photo / Los Angeles Tourism & Convention Board
Are you both a city and nature lover? If you're planning a visit to the United States of America, there are plenty of natural surroundings close to urban environments you can enjoy without having to venture very far.
Here are some of the best urban outdoor experiences the US has to offer:
Los Angeles, California
Fryman Canyon is one of the closest hiking trails to LA, with the paved, tree-lined Betty B. Dearing Mountain Trail wrapped around the hillside with the expanding valley below.
Kenneth Hahn State Recreation Park can be entered off La Cienega, with Gwen Moore Lake on the right. As you journey through the park, take in the views of Century City, Downtown LA and the distant San Gabriel Mountains.
Griffith Park overlooks the city and has a number of different hiking trails that weave up into the hills. For a memorable off-road run, take the Hollyridge Trail that leads from the Observatory parking lot to the summit of Mount Hollywood, the highest peak of the park. The run takes around 40 minutes and once you arrive, you'll be rewarded with spectacular views of the entire Los Angeles Basin.
Portland, Oregon
Portland has plenty of trails on offer for keen hikers. Located about 10 minutes from downtown, the 5100 acre Forest Park boasts forests boasts more than 130 kilometres of hiking trails, including the Wildwood Trail, a National Recreation Trail connecting historic Pittock Mansion, Hoyt Arboretum and the Audubon Wildlife Sanctuary.
Along Portland's southwest border lies Tryon Creek State Park, a 670-acre forest with a fully staffed nature centre and a network of trails winding past trickling streams.
The Intertwine - the name for the Portland region's interconnected system of parks, trails and natural spaces - provides a dynamic (and positively encyclopaedic) list of outdoor excursions, making it easier than ever to plan your visit.
Use the interactive trip planner for favourites such as Council Crest Park, Oaks Bottom Wildlife Refuge and Reed College Canyon - or click on "Find an Adventure" to walk, hike, bike, bird or paddle your way around the area.
San Francisco, California
With more than 73,000 acres of magnificent terrain at San Francisco's doorstep - 5000 of those acres within city limits - hiking enthusiasts can go on a day-long walkabout and still make it back to civilisation in time for the opera.
Start in the famous Castro area, take the hidden trail up to Twin Peaks, explore a eucalyptus forest and soak in panoramic views of Golden Gate Park, the Golden Gate Bridge and downtown San Francisco.
Leafy Lombard Street is great to walk up and down on as well as the Lyon Street Steps.
Just minutes away from downtown San Francisco and easily accessible by public transportation, the Golden Gate National Recreation Area has become the most popular park in the United States National Park system, hosting more than 20 million hikers, bicyclists, campers and tour-goers each year.
By comparison, Yosemite National Park hosts three million visitors annually.
Serious hikers can opt for the hiking trails in Gerbode and Tennessee Valleys in the Marin Headlands - a wanderer's paradise about 30 minutes from downtown San Francisco. The wilderness is rich with wildlife here and it is not uncommon to spy a black-tailed deer, bush rabbit, red-tailed hawk or other bird of prey. Even a bobcat or two may make an appearance on a nice spring or summer day.
To round out the hiking experience, what could be better than spending the night under the open stars?
Chicago, Illinois
Chicago has over 320 kilometres of on-street buffered and protected shared bike lanes, including a 30 kilometre Lakefront path along Lake Michigan.
By the year 2020, the city hopes to increase the size of the bike lanes to a staggering 1038 kilometres city-wide, which would officially make it the most biker-friendly city in the USA.
Just off beautiful Lake Michigan, you can kayak through canyons of skyscrapers and architectural wonders, or explore the waters.
If you're looking for an easy going walk on land, the Chicago Riverwalk trail in downtown Chicago is an easy way to experience the vibrant city while exploring some of its more nature-oriented offerings. This trail will take you only 2.5 hours to complete.
Denver, Colorado
The Rocky Mountains are Denver's backyard playground, offering outdoor adventures, spectacular beauty and Old West history just a short drive from Denver. The Red Rocks Park and Amphitheatre in particular is a local favourite for hiking amid the giant boulders and is also loved for its unforgettable concerts under the stars.
If you're right in the city, a great way to get to know the area and the surrounding nature is to start with a bike ride on the Boulder Creek Path, a 9 kilometre recreational path along Boulder Creek. You can bike, walk, skate or stop and take in the scenery on one of the benches. The creek is also a popular place to go tubing in the summer. This well-maintained trail highlights how much Boulder values a healthy lifestyle and clean, open spaces.