- Like the Grundsund area, also the area of Rilax was part of the frontline during the existence of Hanko Front. The islands that were occupied by the Russian troops can be clearly seen from the area. Nearly no island exists in front of the frontline, which could have been used as a advanced positions. The closeness of enemy however is not so apparent when looking at the fortifications, like it is when being in the area of Grundsund.

- The most interesting structure in the area is the structure number 415. According to the map symbols, the structure was a machine gun bunker/dugout. However structure 415 is not just a single structure, but group of structures that form a base of some sort. Quite surprisingly the area also contains a gun position, from which the fortification map remains silent about. When looking at the gun position, it would seem that it was dug to the ground and a concrete base for the gun was cast to the bottom of the pit. The remains of the gun position however is so badly covered with vegetation and with dead plant parts, that it is impossible to see the possible concrete parapet, without digging the ground in order to reveal the gun position more.

- The gun position has been build so, that it faces towards the island of Bengtsår Prästön and it is situated very close to the shoreline. The area also holds other dugout remains, which are in a very bad shape due to the dead plants piling into the remains. Because of this, it is quite difficult to estimate the meaning of different structures.

- The gun position 42, a & b, is another interesting structure in the area, although it isn't completed. The gun positions have been mined ready, but to finish the positions there hasn't been enough time. The gun positions in question are located on top of tall rock, from where there has been a good view towards the Russian held islands. The mined pits are now covered with water, just like in many other areas where the mining job has been completed.

- Looking at the fortification map, one can see that a anti-tank obstacle line has been also marked to the area. No traces from this obstacle line can be found from the area.

- Structure 470, a, can be found near of the memorial to the Naval Battle of Riilahti. The memorial includes two different stony memorials. The stone cross commemorates the Russians, who took part of the battle. That cross was revealed in 1870. Next to the memorial for the Russians, stands another memorial, which commemorates the Swedish sailors who participated to the battle in 1714. That memorial was revealed in 1928, at the initiative of the head of the Bromarv Civil Guard (Suojeluskunta). Both of the memorials survived the battles of Hanko Front without damage, even when located in the frontline.

- Description found from the Wikipedia of the Battle of Gangut (Naval Battle of Riilahti).

- My own personal notes below are based on the situation in the defensive line, during the years 2005 and 2006.