Seattle is startlingly immaculate. Wide, clean streets cascade down to the busy waterfront in Downtown. People are friendly. They smile and laugh, and honking cars are a noticeably rare occurrence.

The city of 3.8 million people is undergoing a face-lift, with dozens of cranes stretching into the serene skyline, but the capital of Washington state has retained its identity as a long-held bastion of progressiveness.

Nestled in the shadow of the Pacific Northwest's mountains of forests and known as The Emerald City because of its overwhelming greenery, Seattle spearheads LGBTQI rights and was one of the first cities in America to legalise marijuana.

Home to corporate giants Boeing, Starbucks, Microsoft and Amazon, and the birthplace of Jimi Hendrix and grunge, Seattle has become a big city without losing any small-town charm.

The city now hosts the annual Upstream Music festival - the brainchild of Microsoft co-founder Paul Allen.

Into its second year, Upstream takes over the city's oldest neighbourhood Pioneer Square in a fashion much like the seminal South by Southwest in Austin, Texas.

Around 15 venues hosted more than 300 upcoming and established acts from June 1 to 3, with this year's event headlined by Miguel, Jawbreaker and The Flaming Lips.

West coast rapper KYLE brought thousands of fans to delirium at the festival's main stage behind the CenturyLink Field on Friday evening, while around the corner Canadian soul-singer Nuela Charles played a more intimate gig for a few dozen captivated people in a bar.

Over the weekend DJ's and hip-hop dancers took over Occidental Square in the golden light of dusk, punk bands played in small cafes and bars in the early afternoon, and thousands of festival-goers traversed the network of venues to find whatever genre of music they desired.

But the city is much more than a home for a cool annual music festival.

Tourists and locals flock to Seattle Center in Uptown, built for the 1962 World's Fair. Headlined by the 184m Space Needle, the precinct offers over 15 hectares of open space and other attractions, including the Museum of Pop Culture (MoPOP), Chihuly Garden and Glass.

The Space Needle offers incredible panoramic views of the city skyline and across Elliott Bay to the mountains and forests beyond where, on a clear day, the 4026m Mt Rainier looms in the distance.

MoPOP celebrates the immense talents of locals Jimi Hendrix and Nirvana, and has a range of rotating displays such as a horror film history, and a Marvel exhibition.

Chihuly Garden and Glass is a winding maze of glass art created by Dale Chihuly, from nearby Tacoma.

Adjacent to the Space Needle, stunning glass structures and ceilings line the rooms, while the outside Glasshouse is speckled with glass flowers and suspended sculptures.

Back near Pioneer Square, the warm and engaging hosts at Bill Spiedel's Underground Tours provide a walk through subterranean Seattle.

Visitors can marvel at the skylights built in the 1880s to allow underground shopping - the purple glass still visible in some areas of Pioneer Square.

Back up the hill, Pike Place Markets presents locals and travellers with a multi-level maze of farmers markets, food and craft stores.

The top level entrance is a sprawling, open air fish market that spills onto a heaving street full of diverse offerings such as Russian pastries, cheese stores, deli's and baked goods.

Art lovers can take a five minute stroll back into Downtown to the Seattle Art Museum, where patrons are immediately met with two striking pieces. Andy Warhol's Double Elvis sits astride a huge wall, a life-size portrait of Elvis Presley in his Hollywood heyday.

A quick 180-turn lands on the breathtaking Untitled by enigmatic American artist Jean-Michel Basquait. On display for the first time on America's west coast, the 1982 painting by the then 21-year-old is a cacophony of movement and colour and a comment on Black culture in America, as relevant today as it was then.

As the sun sets and hunger creeps in, diners can wander up to the corner of 4th Ave and Virginia St for the twin delights of restaurateur Tom Douglas - Dahlia Lounge and Lola.

While Lola offers more of a seafood and Mediterranean cuisine, Dahlia Lounge is a classic, refined dining space with a dazzling array of drinks to pair with fresh, local ingredients.

Elsewhere, the neighbourhood of Capitol Hill, a 10-minute drive from Downtown, is lined with charity stores, bars and cafes, and dappled with Pride flags.

Armies of volunteers meticulously clear litter and rubbish to prepare the diverse district for the annual Seattle PrideFest to be held in late June.

Seattle is the sort of city that visitors don't want to leave. It may not be the tourist haven New York or Los Angeles is, but just a few days in the bubbling city and it feels like it could one day be home.

IF YOU GO

GETTING THERE: Virgin Australia flies to Los Angeles from Sydney, Melbourne and Brisbane, with wi-fi offered on all three routes. Delta Airlines flies you from LA to Seattle in around 3 hours.

STAYING THERE: Loews Hotel in the heart of Downtown gives visitors a great base. It's surrounded by a cluster of bars and restaurants. A 10-minute stroll leads to Pioneer Square in one direction, the pier in another direction, and Pike Place in the other. Visit https://www.loewshotels.com/hotel-1000-seattle

PLAYING THERE: Spend a day at Seattle Center to visit MoPOP, Chihuly Gardens and Glass, and take in the incredible views from the Space Needle (www.seattlecenter.com). Explore underground Seattle and the waterfront, stroll through Capitol Hill and stop at bar for a quick drink or bite to eat. Marvel at the collection in the Seattle Art Museum (www.seattleartmuseum.org/), and dine at nearby Dahlia Lounge (https://www.dahlialounge.com/).

The writer travelled as a guest of Brand USA and Virgin Australia.