Here's a list located hidden spots that were discovered from wilkinson's blog

Secret places. The orb may be used to explore a wide range of places that are usually out of range or in a location that should normally be quite far away. Free players have access to their own areas of play and may see some intriguing information.

What is NPC? It is a shortcut of Non-Player-Character. Sometimes NPC are not visible when viewing from the orb. This is due to the fact that NPC can only be viewed by navigating to your mini-map. The orb will not be able to view structures that you cannot see from the mini-map. For example, the orb cannot view the tower on the roof of the Al Kharid palace. If one logs out, then logs back in at the end of a Dungeon area (such like the runecrafting altars) The player has the OSRS gold  option of using the orb to see into other areas. Players are not able to use the orb into Fist of Guthix. There will be a message: "You cannot use the orb in combat" in the event that you try to do so. The orb can also't be used within the Corporeal East's dungeon , before you have completed summer's End.

Here's a list located hidden spots that were discovered. It was possible to peek into the Tutorial Island bank from South of the Wizards' Tower once but no bankers.

If you are standing in the area to the North of the Blast Furnace and using the orb of Oculus to gaze further North you will see the Candlelight Chapel that is an old retired Random event. Oddly enough, what appears is the Gravedigger Random Event, seems to be to the West of it. In the distance, to the North-East of the chapels and the chapels from Temple Trekking can also be observed. To the east and west of the Furnace are caves that are part of an Eagle's Peak quest.

You can see an unfrozen mountain in the area which is where the Tree Gnome Village is supposed to be located, on the top floor of the Watchtower, after completion of the Watchtower Quest, which could possibly have been Eagle's Peak or simply a glitch.

The 2005 Christmas celebration can be seen to the East, from the third space of Pyramid Plunder. The agility track from the Halloween celebration of 2007 will be visible in the very far East of the scarab area at Uzer Mastaba.

The 2010 Easter event can be seen from a barbarian assault. If you standing at the East corner on Fourth Floor of Stronghold of Security and looking towards the East, you'll see the former TzHaar Theatre, which was the venue for TzHaar-Hur's play and is still using the old TzHaar City image.

The Draynor Bank Robbery Cutscene section can be found in Burthorpe Games Room. The Path of Glouphrie goblin war cutscene can be seen at the East part of the games room.

On the south-west side of Sophanem's banking facility, you'll be able to observe the broken version of the buy RS gold bank, only accessible through Contact.

On the other side of the South-East it is possible to see the ruins of a castle and railings that appear to represent part of the North end of the castle. It was there during the Holy Grail.

If you look as far the North-East as it is possible you will see part that appears be the lower level of Saradomin's camp in the God Wars Dungeon.

And if you want to view the Player Moderator room, you'll have to look towards the South-East.