Riga, Latvia — In a move that has surprised urban planners and perspiration experts worldwide, Riga has unveiled the Baltic region's largest underground bicycle tunnel network, designed exclusively to connect the city’s sprawling array of backyard saunas. Officially inaugurated over the weekend, the 672-kilometer underground passage is hailed as a 'bold leap forward in recreational mobility and thermal efficiency' by local cycling zealots and sauna aficionados alike.

The Riga Sauna Tunnel Initiative, affectionately dubbed 'SaunaCycle Superhighway' by locals, weaves a labyrinthine path beneath the city, providing dedicated bicycle access to over 3,000 privately-owned saunas—16% of which are rumored to hover precariously close to being classified as 'ceremonial sweat temples'.

'With this initiative, Riga is leading the charge in both eco-friendly transportation and cultural integration,' announced Gunārs Pelēcis, Deputy Minister for Leisurely Affairs, while standing mysteriously dry near the entrance of the first section of completed tunnel. 'Never before has such a large public works project been dedicated entirely to maximizing sweat productivity and minimizing vehicular sauna-blocking.'

Funded by the European Union's perplexingly niche 'Cycling Sauna Access Beyond Borders Fund', the project overcame several unorthodox engineering challenges, including tunnel waterproofing presumably resistant to sauna-induced steam bursts and strategically placed cucumber infusion points every 100 meters.

Local citizens have embraced the project with enthusiasm tinged with bewilderment. 'It's a game-changer,' said Maija Kalniņa, a daily cyclist and part-time sauna sage. 'Now, I can pedal leisurely to my sauna without dodging traffic or worrying that my towel will catch a breeze and turn me into an accidental exhibitionist.'

In an odd twist, the project has spurred the creation of the 'Sauna Speed Trials', a competitive league where participants race from sauna to sauna, judged by both speed and the amount of sweat beaded on their skin upon arrival. Organizers promise the first 'Steamy Sprint Classic' will be held next summer, with participants required to pedal in regulation bath slippers.

However, not all responses to the tunnel have been enthusiastic. Critics, such as the newly formed group 'Citizens Against Underground Sweating', have questioned the project's exhaustive use of public funds while Riga's above-ground bicycle lanes remain peppered with potholes affectionately dubbed 'circular wormholes'.

Nonetheless, public interest remains high, with the tunnel already seeing an average of 1,500 sauna cycles per day, according to city officials. To accommodate the demand, the city has also taken the unprecedented step of installing the world's first bicycle parking structure with integrated towel drying facilities and cold plunge vending machines.

As the tunnel's influence gradually permeates daily life in Riga, supporters believe its success could prompt similar projects in other Baltic capitals. Vilnius and Tallinn are reportedly considering aggressive sauna cycle possibilities, though they remain coy on the revolutionary concept of sauna-tunnel horse carriages.

'While residents may get used to sauna cycling,' mused Pelēcis, 'one thing is certain: the SaunaCycle Superhighway smell will endure as a testament to our communal dedication to both physical fitness and Nordic-inspired steam.' Perhaps this indeed marks the dawn of a transformative era in Latvian transportation and perspiration culture—two elements that no one had previously thought to combine, but are now forever entwined beneath the streets of Riga.