The oldest archaeological finds in Ascona (at S. Materno and S. Michele) go back to the beginnings of Late Bronze Age. During the expansion of the cemetery in 1952, a necropolis was discovered at S. Materno, with 21 cremation urns were discovered. The urns were either simply buried or covered with a stone slab box. They contained cremated bones and, in some cases, bronzegrave goods. Of particular interest are the bronze brooches, which are among the oldest that have been found so far in Switzerland. They also provide important evidence for the relationship of this area to the cultures of the Italian Peninsula. The grave goods have similarities with those from the final phase of the so-called Canegrate culture (named after a large necropolis inMilan). However, the materials used are those of the late Bronze Age north of the Alps. This allowed the cemetery to be dated to the period between the 12th and 10th Centuries BC and points out that Ascona took part in trade over the Alps through the Val Mesolcina and over Lake Maggiore with the Po Valley.
Similar objects were found by exploratory excavations in the late 1960s on the castle hill of San Michele. Both fine ceramics and coarse pottery were discovered, which suggests that this area was settled during the Late Bronze Age, even if there is no evidence to the municipal structures. Remains of walls and clay from the Balladrum hill are the only Iron Age objects found in the municipality. However, the exact age is unknown. The only item that has been conclusively identified is a single flagon from the 6th to 5th Century BC.
From the Roman Empire, a necropolis with 38 tombs at the foot of the Castle of S. Materno was discovered. The equipment found near the graves points to the period in the mid-1st or 2nd Century AD. The necropolis was probably associated with a manor.
In 1979-80, an excavation at the church of S