It's one thing to get on an airplane and fly someplace new. We do it all the time. But there's only so much you'll see from 37,000 feet. Once you arrive, you really get to know a place when you've got "boots on the ground." Here are a few of my favorite places to explore the old-fashioned way: on foot.

A. Kauai's Napali Coast. On my first trip to Hawaii, my friend David Pike and I drove to the end of the road on the North Shore of Kauai, near Hanalei. With little more than a tent, a backpack, a six-pack of San Miguel beer and a couple of grass mats, we hit the trail. This is an incredible hike along sheer cliffs and past stunning waterfalls. We spent the first night at Hanakapiai Falls, which is about four miles from the parking lot. The next day, we pushed through to Kalalau Valley at the end of the trail -- an additional seven miles. Around every corner was a new eco-system and microclimate. This is a strenuous hike -- and it's best to do it in the summer. Rains can wash away parts of the trail -- and you do NOT want to fall. www.napali.com

B. The Valley of 10,000 Smokes. Right here in Alaska, this hike in the heart of Katmai National Park is a "must-do." Start at Brooks Lodge, where all the bears congregate to feast on the salmon swimming upstream. Catch the bus for a 37-mile trip up to the visitor center. You can look out over the desolation caused by the 1912 eruption of the Novarupta volcano. But you need to hike down to the valley floor to really see the hundreds of feet of pumice -- and how the Ukak River cuts through it, forming a mini-Grand Canyon. It's incredible. The tour allows time for a hike down and back, as well as a sandwich lunch at the visitor center.

Other national parks have incredible hikes as well, including Crater Lake National Park in Oregon. Several of my friends worked at the park, where they said the hike from the rim down to the water's edge was "One-point-one miles down and 11 miles back up!" Find other national parks: http://www.nps.gov/findapark/index.htm

C. San Francisco. It's hard to put my finger on the best walking itinerary, since I've walked all over the City By The Bay. Typically, I end up walking because I can't catch the cable car by Union Square -- it's always crowded. Last time, we walked (almost crawled) up Nob Hill to Grace Cathedral. Inside, a Swiss girls choir was practicing for a performance -- and it was wonderful to listen in. We later caught the cable car for the ride down to Fisherman's Wharf.

We returned to Nob Hill for a "Vampire Tour" led by "Kitty Burns" (Mina Harker), who details 100 years worth of San Francisco history, with some extra-special haunted legend! This two-hour tour is perfect for the vampire lover in your family. www.sfvampiretour.com

Whether it's an all-day stroll in Golden Gate Park, a walk through Chinatown or a shopping marathon around Union Square, you simply cannot go wrong walking in San Francisco. It's everybody's favorite city, including mine.