Both the Rock Church (the Temppeliaukion kirkko) and the Chapel of Silence are beautiful and (at least in my opinion) iconic structures in central Helsinki. We recently visited (and enjoyed) both on an autumn afternoon.
The Temppeliaukion church was constructed in the late 1960s by encavating a rocky hill in Töölö (central Helsinki – quite near Töölö Towers where we stayed for our first month in Finland). As a result it appears partly submerged, with just a low rocky wall (encircling the church’s roof and sky-lights) visible from the north. In fact, a path from the western-side of the church allows visitors to view the church complex from above and get good views of the surrounding neighbourhood. Inside, the church has a wonderfully rich feel – the walls are predominantly untreated rock (with even the drilling and blasting holes undisguised) and brass (or copper?) is widely used, giving the interior a beautiful rich orange hue. It was also interesting to note the drains discretely installed along the floor edge to trap water running down the walls. Apparently the bare rock walls have excellent acoustic properties, making the church a favourite concert venue – I imagine that it would be a great place to listen to beautiful music. As an aside, it was interesting to see that one of the streets adjacent to the church is Tunturinkatu – which means treeless (or fjell) hill – reflecting the characteristic of the area before the church was built there. Entrance to the church is free (as all churches should be!), access is easy from the Kamppi Metro station or the 8 Tram (the address is Lutherinkatu 3 – just pop it into Reittiopas for directions), and you can find the opening hours on the parish’s website (it’s in Finnish on the right of the page, but Google Translate can solve that if you can’t make it out).
The Chapel of Silence was recently completed in the Narinkkatori square in Kamppi, as one of the city’s World Design Capital projects. This is maybe the most appropriate place for this building, since the chapel is located in what is probably one of the busiest and noisiest spots in the city – but once inside you can’t tell that anymore. The chapel is predominantly constructed from wood – the exterior cladding is spruce, the interior is paneled in alder, and the pews are constructed from ash (detailed here). While being isolated from the noise outside, the chapel is very sensitive to sounds inside – unzipping a jacket sounds really loud, so be sure to undo any velcro before stepping inside since that would surely sound like a chainsaw in there! While the pew benches are maybe not conducive to sitting there for a long time, it was a welcoming spot, and I imagine that it could be a popular place for those seeking a few moments of quiet to be peaceful or prayerful. You can visit the chapel on weekdays from 7am–8pm and on weekends from 10am–6pm (although maybe check VisitHelsinki for updated hours). You can easily walk to the chapel from the Kamppi Metro station or the central railway station (aim for corner of Simonkatu and Yrjönkatu – you can see it easily from there). There are also representatives from the local parish and the city’s social services available every day for those who need someone to talk to – it sounds like a good idea, although I’ve no clue if you’d find someone speaking English there.