Free entry at Everglades National Park and Shark Valley on Saturday

Cool weather during the dry season is the best time to explore South Florida's stunning River of Grass.

Get in free at Everglades National Park (and all U.S. National Parks) on April 20 for the first day of National Park Week. That’s a deal since the fee recently increased to $30 per car.

There is so much to appreciate about this delicate ecosystem, which is the source of our drinking water. Reservations are not required unless noted. For more information, visit NPS.gov/ever or call 305-242-7700.

Homestead main entrance:

Enter the park off U.S. 1 (40001 State Road 9336) and have a look around the Ernest F. Coe Visitor Center. At the Royal Palm Visitors Center, see lots of wildlife along the Anhinga Trial on a free, 50-minute ranger-led tour at 10:30 a.m. daily. Explore the junglelike hardwood hammock just a few steps away.

Shark Valley:

This area is the heartland of the Everglades, named because its water flows southwest toward Shark River. Take the Meteor Shower Bike Ride from 7 to 10 p.m on Saturday along the 15-mile loop (weather permitting, reservations required at 305-221-8776). Or, take a tour with a ranger 1:15 p.m. daily through April 30 to see to see countless alligators. Better yet, hop on the tram or rent a bike and pedal the 15-mile loop. Climb the observation tower to get an expansive view of the sawgrass prairie. Call 305-221-8455 or go to SharkValleyTramTours.com for prices and times.

Lifetime Senior Pass:

Those 62 and older can get unlimited free entry to all parks for $80. A 12-month pass is $20. Passes also are free for military and fourth graders. Get them at the Ernest Coe Visitor Center at the Homestead entrance or go to Store.USGS.gov/senior-pass.

Other fee-free days this year will be Aug. 25 for the National Park Service's birthday, Sept. 28 for National Public Lands Day and Nov. 11 for Veterans Day.