IT's hard to calculate whether there are more tourists pressed five-deep along the dock at San Francisco's Pier 39 watching the sea lions or whether there are more "sea-lebrities" eyeing the tourists from the floating pontoons.
Suffice to say it's a mammal mosh pit. People have been flocking to San Francisco since the 1849 gold rush.
The sea lion population is a more recent addition.
They started arriving at Pier 39 after the 6.9-magnitude Loma Prieta earthquake in 1989, forcing a relocation from their Seal Rocks home north of the city's Ocean Beach.
Initially the boaties and shipping operator were at war with the fat, lazy and smelly new arrivals.
But the boisterous, barking sea lions have since become one of the city's major tourist attractions.
The two-metre long, 300kg protected beasts enjoy their celebrity status, with up to 1700 taking up residence depending on the season.
More than 18 million tourists visit San Francisco each year, to photograph the sea lions, visit Alcatraz, cross the Golden Gate Bridge, indulge in the foodie scene, or just play and twist along Lombard Street - the world's most crooked road.
It certainly has worldwide appeal with Trip Advisor's Travellers' Choice rating Alcatraz number eight and the Golden Gate Bridge number 10 on its World Wonders 2015 list.
Other must-visits are the crush of groovy cafes, bars and clubs in the famed village of Haight Ashbury, which inspired the music and writers of the beat generation and the hippies of the Summer of Love in the late 1960s.
Also worth a stop is San Francisco's Silicon Valley, which has become the site of the latest "gold rush" with some of the biggest global digital brands and hundreds of technology start-ups occupying the southern suburbs of the Bay area.
Here's a list of the top 10 things to do in San Francisco:
1. Night tour of Alcatraz
This former island prison is only accessible by boat but the short trip is worth the journey to see where Al Capone and other infamous criminals were incarcerated. The evocative night tour with audio from former inmates brings the rocky outcrop to life.
2. Fisherman's Wharf and Pier 39
In addition to the obligatory sea lion stop, spend the day strolling, eating, drinking and shopping around this main tourist zone which also boasts an aquarium, Madame Tussauds and Dungeon.
3. Cable car ride
Only a few of the original cable cars survive and you will have to queue but the trip is worth the wait as you can hang out the side and take photos throughout the journey. And it's a cheap way to get from downtown to the wharf.
4. The Golden Gate Bridge
It's actually a burnt orange colour but spending some time on and around the Golden Gate Bridge, the nearby harbour front and the former military area known as the Presidio is fun and informative. If you take a cruise under the bridge expect to meet Karl, the name locals have given to the ever-present fog that rolls across the Bay.
5. Open-top tourist bus ride
Taking an open-top bus ride, or three, with live commentary around the city is a quick, easy and fun way to get your bearings and check out the sights that you want to go back to and spend more time enjoying.
6. Hippie-central Haight Ashbury and Golden Gate Park
Lined with Victorian and Edwardian wooden houses, Haight Ashbury is synonymous with rock and roll and the hippie-drug culture from the 60s and 70s. The nearby Golden Gate Park is a wonder of gardens, museums, memorials, windmills and a bison enclosure.
7. Giants baseball game
With a trio of World Series victories (2010, 2012, 2014) to their credit the Giants are hugely popular and their home ground at AT&T Park is close to downtown and the waterfront where home runs can land in the drink. Depending on the fortunes of former NRL star Jarryd Hayne you could also sell a kidney to secure a ticket to a 49ers NFL game.
8. Napa, Sonoma and Mendocino
Heading north over the Golden Gate Bridge you will get to the renowned Napa and Sonoma wine-growing valleys after about an hour. Another hour on the road north will take you to the less touristy and more relaxed Anderson Valley and the Mendocino wine region.
9. Computer history museum in Silicon Valley
Silicon Valley is where Google, Facebook and Apple are all working on their next big digital breakthrough. This museum in Mountain View provides a fascinating look at the development of computers from the 150-year-old Babbage Engine through to Google's driverless cars.
10. Yosemite National Park
It's a three-hour drive and worth the effort to see the giant rock formations, verdant valleys, icy waterfalls and wildlife. You will see deer, chipmunks, squirrels and bears if you're lucky. Spend at least two days. The hikes are breathtaking.
GETTING THERE
Qantas flies non-stop from Sydney to San Francisco five times a week, which is more convenient than flying to LA and getting a connection.
STAYING THERE
The luxurious and historic Palace Hotel is brilliantly located downtown and close to Union Square, city buses and cable cars. It has an elegantly massive glass-covered atrium cum dining room and a bar famous for the giant and priceless Pied Piper painting.
PLAYING THERE
Get a San Francisco CityPASS or GO Card - both are multi-attraction passes that offer cheap transport and entry to many of the city's tourist sites.
* The writer travelled with assistance from Visit California.
AAP