There are still quite a few remnants of the Russian influence, one being the marking of the fairways between the islands. This is mainly done using the 'cardinal system', where obstructions are marked with black and yellow marks, the 'order' of the black and yellow indicating where the obstruction is:
This is a South cardinal, the black underneath the yellow tells us that the mark is to the south of the obstruction.
The cardinal system is still extensively used worldwide, but generally only to indicate separate obstructions, not the course of the fairway. This is nowadays usually done with the lateral system, using red and green buoys. In the Åland Islands the lateral system is only used on the newer fairways, the Russians used (and apparently still use) the cardinal system almost exclusively.
A more visible remnant of the Russian times are the Bomarsund ruins. As Åland was the westernmost outpost of the Russian empire, they wanted to build a fort here to defend against naval attacks and to protect their Baltic fleet. They started building it in 1850, it was to be an enormous fort with 8 large towers. But long before it was finished, in 1854, it was destroyed by a joint British - French force.
From the ruins of the tower, one has a great view of the Åland skärgård:
At the foot of the tower, in the bay called Notviken where the Russian fleet was to have been anchored, there now is a guest jetty on the rocks where we are now tied up on a stern buoy.