You would think if gravity had its way, the village of Gandria would slide into Lake Lugano, so precarious is its hold on the steep slope above the shore.
But residents and local officials are less concerned about the weak and crumbling foundations than the primitive plumbing. Sewage flows untreated into the lake.
Gandria's cheery pastel buildings clinging vertically to the shore are reminiscent of the Italian Riviera.
It is a spectacular setting that attracts throngs of tourists each year. Much has been written in praise of Gandria, but nothing about its murky side.
Along with one other village, it is the only place on Lake Lugano which does not treat its wastewater.
The sewage passes through a simple tank where coarse objects and particles are filtered out, before flowing back into the lake.
The sewage problem is a well-kept secret and could have a disastrous effect on tourism - the village's main source of income - if it became widely known.
"It is the biggest problem we have concerning the lake, but it doesn't greatly affect the quality of the water," says Lugano water engineer, Tiziano Mauri.
"Lake Lugano is sensitive to pollution and eventually the lake could die if the amount of bacteria and other micro organisms in the water continues to increase."
"But we are still far from this critical level," he says reassuringly.
In support of Mauri's claim, Lake Lugano has for the past few years ranked amongst the cleanest Swiss lakes for swimming.
And people living in the towns along its shores, including Gandria, get their drinking water from it.
Eel and trout
The lake is well stocked with fish, including eel, carp, roach and trout.
Professional fishermen brought in a healthy catch last year of 28 tons, and freshwater fish from the lake can be found on the menus of many lakeside restaurants.
Elda Pachinn who runs the Gandria restaurant, Locanda Gandriese, only smiles and shrugs her shoulders when asked about the water quality.
"We've always put up with things the way they are," says Pachinn. "We have many old people in the village who have lived up to 100 years of age. Nobody ever died because of the water!"
Even though Pachinn and Mauri downplay the seriousness of the problem, a decision has finally been taken to treat Gandria's sewage.
Mauri's office has been awarded the contract to build a three-kilometre-long underwater pipeline to connect Gandria with a water treatment plant in Lugano.
It is one of the final steps in a process the Ticino authorities began about 20 years ago to clean up the canton's lakes and rivers.
Gandria was one of the last places on the list because the village simply could not afford to tackle the problem.
"It was too expensive," says Mauri. "Hooking up Gandria to Lugano's water treatment plant costs about SFr3.5 million ($2.7 million).
"A small community like Gandria simply couldn't afford it."
The turn of events came about because of a recent decision by the 200-person community to merge with its big neighbour, Lugano.
The pipeline should be completed in a couple of years' time, and should calm the waters around Gandria.
swissinfo, Dale Bechtel
Gandria has a population of about 200.
It is located only a few kilometres east along the shore from Lugano, Ticino's financial centre.
The village lives from tourism. It has several hotels, restaurants and souvenir shops.
Many visitors come to Gandria by boat and hike back to Lugano along footpaths hugging the shoreline.
The Ticino village of Gandria is one of two villages on Lake Lugano which still does not treat its sewage.
Experts say it is the largest problem affecting the water in Lake Lugano, but it is still one of the cleanest lakes in Switzerland.
A planned merger with Lugano will provide the village with the necessary funds to build a pipeline connecting it to a water treatment plant in the neighbouring city.