Loop B was recommended by the information desk since we had a stroller as the only possible trail with the least amount of stairs. Loop B goes around the lower lakes area and is supposed to take 3-4 hours. It ended up taking us over 5 hours instead. All of the trails were well marked and there were guard rails on some of the hilly parts, but hardly any guardrails on the wooden walkways that composed most of the lower part of the loop, so very young children walking on their own is not a good idea. The most 'intensive' stairs were at the last part of the lower loop, near the last set of waterfalls. The waterfalls were literally next to the wooden walkway and there is a picture below to give yourself an idea of the stairs; not steep but these keep going for a while. The wheels can get 'stuck' between the boards so we both had to help carry the stroller at times. This is towards the free boat that takes you back across the lake towards entrance 2.
After the free boat across to Entrance 2, we took the park-provided bus back towards Entrance 1 where we parked. The bus first took us up to the top of the lakes area to the start of the trail at the upper lakes, so we got to see both the lower and upper lakes. I can definitely say the upper lakes pathway was for walking only (no strollers) and read it was 4km from top to bottom. There were plenty of stairs and raised up twisting walkways through the woods.
The park-provided bus doesn't go all the way back to Entrance 1 (not sure why the sign said that) as it stops at a bend in the road next to the highway with a coffee shop and some picnic tables. From there it’s a 1 km trail (mainly downhill with minimal stairs) back to the actual Entrance 1. This path basically backtracks across the lower lakes area were we just walked below, except you are much higher up. There were some good views of the waterfalls from this upper path. The trail ends at the tallest waterfall (where we began). The lighting in the afternoon wasn’t the best for photos on the last part of the trail, but the views are still amazing.
Plitvice Lakes National Park is definitely a unique place in the world with terraced lakes and hundreds of waterfalls! The park has a great website which includes a virtual tour showing many of the highlights. Visiting is highly recommended, especially if you like waterfalls. The crystal clear waters of the lake are amazing as well. We paid around $1 per hour for parking (7 Kuna per hour), but there are also public transportation options or tours you can join. There were some taxis hanging around as well. The park-provided buses between the entrances finished at 7pm and the boats are also included in the ticket price (which varies by season). Taking the boats were the only time our ticket was checked.
Overall, I am glad we took the trip, but would suggest giving yourself plenty of time if using a stroller. The dirt parts of the path were fairly easy with the stroller, which was maybe half of the whole Loop B. I wouldn't recommend a stroller if visiting when raining or after a large rainfall as the path would probably turn to mud in some places and the stroller could get stuck. All the trails and loops are clearly marked and there will probably be hundreds of other visitors sharing the path with you. The pathway is narrow in places so we had to stop many times to let groups go by.
Only take a stroller on Loop B in good weather and with two adults to help carry it over the rough parts
Leave plenty of time if you are using a stroller or bringing young children, Loop B was supposed to take 3-4 hours and took us almost 5 1/2 hrs. I felt we were moving a long at a decent pace.
If hiking the upper lakes (stroller not possible), take the bus to the start of the path FIRST so you will be walking downhill the length of the 4km trail.
Get there early! We arrived around noon and there were literally hundreds of people at the entrance, especially large tour groups! (and this was not peak season)
Don't buy one of the maps sold near the entrance, a park map with all the trails is printed on your ticket!