Verla is a well-preserved example of a 19th century Finnish wood processing plant. The most renowned product in Finland was the cardboard that was used to print maps on display in Finnish schools. At least, that’s what our resident Finnish traveler - Juha - mentioned over beers in Helsinki.
The mill remains in a mostly original, 19th century state. Because of size limitations, the owners never extended or modernized the mill. Instead, the company slowly phased it out. They continued to operate it in the traditional way until the last workers reached retirement age (1960s).
While interesting and somewhat fitting for a country, that produces loads of timber, Verla is not a great site. It’s relatively recent (late 19th century) and of a rather small scope given the period. The comparison that came to mind is Engelsberg, but that site is a century older.
Getting There
In summer (roughly June to early September), and then only on weekends, there are two daily shuttle rides from Kouvola station to Verla. These continue to Repovesi National Park. Outside summer or on a weekday, I am not sure how you can manage. The only recommendation I found online was to rent a bike.
The bus itself is new and really comfy. It was paid for by the EU. The region tries to boost tourism. On summer weekends, the bus does a morning round (2019: 9:15-10:00, returning 11.40-12:25) and an afternoon round (13:10-13:55, returning 15:35-16:20). 1:30h is enough to visit the site, but the guided tours are not well scheduled with the bus arrival and departure times. To catch my return ride and not wanting to spend the remainder of the day in Verla, I had to cut the guided tour short and left half way through. If you plan to do the same, give the guide a heads up.
In Kouvola, the bus to Verla departs outside the train station and is easy to spot. In Verla, the drop-off point is also the pick-up point for the return trip. In my case the bus ran early, but at each stop we waited for the scheduled departure time. To pay for the ride, you need cash (5€ each way).
To get to Kouvola from Helsinki take a train. These do not run hourly, so expect to spend some time hanging around the train station. After my visit, I continued - again via train - from Kouvola to Petäjävesi (two transfers). What should have been a relaxed trip was quite nerve-wracking because of a delay. I was worried to miss my connection and end up somewhere in the country side. Fortunately, Finnish Rail made an effort to ensure the connections and all worked out fine.
Final remark: Getting public transport information in Finland is harder than it should be. There is no central search engine available. You need to check bus connections and trains separately. Also note that Google Maps is incomplete. If you can choose between bus and train, I would opt for the bus.