Two different questions

Most visited and most popular are not the same list, and this site keeps them apart. The first is ranked on published visitor counts alone and contains only attractions that publish one. The second combines visitation with public interest and tourism significance, so it includes well-known places that count nobody at the gate.

Rankings this site does not publish

Several obvious pages are missing on purpose. Each would require a signal the database does not have, and building it from what is available would produce an ordering that looks authoritative and means nothing.

Most Popular Family Attractions
No sourced signal exists for how suitable an attraction is for children. Assigning it by category would be a guess presented as a ranking.
Most Popular Hiking Destinations
Trail length, difficulty and elevation are not in this dataset. A hiking ranking derived from visitor counts would rank car parks rather than trails.
Most Popular Scenic Attractions
There is no measurable definition of scenic, so any ordering would be arbitrary.

These will appear if and when the underlying data does. That is the same test every ranking here had to pass, and it is described in full on the methodology page.

Published rankings