HelTri Cup

Deep and clear, Kaitalampi stretches like a secluded Nordic fjord through northern Espoo. Held across this freshwater basin in the Uusimaa region of southern Finland, the HelTri Cup provides open water swimmers with a sheltered evening test on tranquil inland waters. Organised by Helsinki Triathlon ry, the cup is an open competition series where club members race for free and visiting swimmers take part by paying an entry fee. Across its wider calendar, the cup includes varied distances of 50, 200, 400, 750, 1,000, and 2,000 metres. The series gathers adult swimmers in age brackets ranging through the 20s, 30s, 40s, 50s, 60s, 70s, and 80s, alongside dedicated categories for children and youths aged 9 to 12 and 13 to 16. Kaitalampi has welcomed the HelTri Cup in past summers, including a 2 km open water swim held here in early July 2020.

The HelTri Cup course from the Kaitalampi pier

The open water swimming event of the HelTri Cup takes place on late June evenings, starting when the calm water lies undisturbed under the northern sky. Competitors do not wade into the lake from an open beach; the race begins directly in the water at the end of the wooden pier. Swimmers tread water as the field lines up across the lake basin, awaiting the official signal in absolute forest quiet. The race gets under way with the verbal command to take your marks, followed by the blast of a whistle that sends swimmers outward into the deep channel. The adult course covers approximately 2 km and traces an elongated counter-clockwise circuit that follows the natural geometry of the basin.

Swimmers stroke down the right-hand shoreline, watching the wooded edge glide past on their right until they reach the turning buoy anchored at the far end of the lake. Swimmers round this distant buoy counter-clockwise, keeping the turn marker on their left-hand side before striking out down the opposite bank toward the pier. Under-20 competitors race right alongside the adults over the full 2 km circuit. Younger age divisions swim their own tailored courses during the same event. Swimmers in the 13 to 16 age group start immediately behind the adult field to complete a 1 km route, heading 500 metres out from the pier to round an intermediate turn buoy before heading back.

Children aged 9 to 12 have their own separate start, swimming a sheltered 200-metre course directly to the pier under the personal escort of a coach. The swim concludes back at the starting zone, where competitors climb out of the water behind the pier and sprint up the bank to cross the timing line on land.

Kaitalampi: clear water, steep drop-offs, and thermal layers

In Finnish, Kaitalampi translates directly as "narrow pond", an accurate description for a body of water that measures 1.3 kilometres in length and only 300 metres across. Covering 12.5 hectares, this elongated basin lies tucked inside a nature reserve that remains a quiet, calm sanctuary removed from city bustle. Instead of sandy shallows, the lake has two primary swimming spots where the bottom falls away steeply just steps from the shore. While the abrupt drop into deep water can surprise first-time visitors, the lake rewards swimmers with stunning scenery and clean, transparent water. Kaitalampi is slightly acidic, recording a pH of 5.9 at one metre below the surface and 5.7 at a depth of five metres.

Because the lake is deep, it exhibits distinct thermal stratification during the summer months. While the surface layer absorbs the warmth of the sun, water near the lake bed stays six degrees lower. Introduced sport fish inhabit these deep waters, including rainbow trout, whitefish, brown trout, and brook trout. The surrounding forest holds other small secluded ponds, including nearby Sorvalampi, a 1.1-hectare water body with a 500-metre shoreline named after the rudd, known in Finnish as sorva.

Luukki nature reserve and the Nuuksio fracture lakes

The western shore of Kaitalampi belongs to a protected 72-hectare nature reserve established in 2002, ensuring that its wooded banks remain wild and undeveloped. Haukkalampi formed in a depression between rocky hills caused by bedrock fractures, creating an L-shaped lake with an eastern section 200 metres wide, a 2.9-kilometre shoreline, and a half-hectare island connected by a footbridge. Mustalampi spans 400 metres by 350 metres over 3.3 hectares, featuring two long bays, two shorter bays, and 1.4 kilometres of shoreline. Another impressive regional basin is Nuuksion Pitkäjärvi, which stretches 6.7 kilometres at an elevation of 27.9 metres. Overlooked by cliffs like Mustakallio and Romvuori rising 60 and 65 metres, it is Espoo's deepest lake, averaging 6.5 metres and plunging to 18 metres northeast of Jäniskallio.

In the valley of Pitkäjärvi, ancient post-glacial waters tell another chapter of local earth history: submerged under the sea after the last ice age, the valley formed a marine fjord before post-glacial land uplift turned it into a freshwater lake. Pitkäjärvi covers 1.71 square kilometres across a length of 4.9 kilometres without any islands, remaining shallow with an average depth of 2.3 metres and a maximum of 5.6 metres along its 13.1-kilometre shoreline. It sustains populations of pike, zander, crucian carp, roach, and crayfish, and motorboats are completely banned from its waters. On foot, Kaitalampi itself sits directly on the Seven Ponds Circuit hiking trail that loops through the surrounding forest from Luukki Manor.

Luukki outdoor area and the ancient lake shores

On race evening, event logistics and post-swim gatherings centre around the communal facilities of the Luukki outdoor recreation area. Beside the water, swimmers find changing rooms, outhouses, and a shared cooking shelter equipped with a grill. It is a welcoming base where competitors can change out of wet swimwear, warm up by the fire, and swap race stories in the forest clearing. Settlement around Espoo's freshwater shores goes back 8,000 years, when Stone Age people built their homes along south-facing shores and slopes to protect themselves against cold winds. During the Bronze Age, the southern part of Espoo was an open archipelago where early communities left behind more than 70 stone cairn burial sites.

Centuries later, shore clay along Espoo Bay supported 19th-century brickyards in Espoonlahti and Kauklahti, while the island of Staffan hosted a joiners' workshop established in 1886 that became known as the University of Soukka. Historic estates grew up along these inland waterways, including Bodom Manor, located about seven kilometres away on Lake Bodom. Lake Bodom spans roughly three kilometres by one kilometre, bordered by the districts of Kunnarla, Röylä, Bodom, Högnäs, and Karhusuo. Further inland, about eleven kilometres away, Königstedt Manor stands on the bank of the Vantaa River, which receives water from lakes like Valkjärvi via the Luhtajoki River.