The Dream Castle was released in 1983 and is quite an impressive playset as it double to twice its size once opened. It came with the pony Majesty and her friend Spike
The Dream Castle was seen in the My Little Pony Special, and has been referenced many times in comics and in art work. It's also depicted on the Collectors Case.
US Dream Castle
The First Dream Castle Playset came with:
Regular Dream Castle Spike
4 ribbons: Blue, Pink, Purple, Yellow (two for use with damsel hat, one for use with the cape) MIP with ribbons can be seen here (the picture is located in https://mylittleponyaccessories.weebly.com/)
Euro Dream Castle
Note: All the items in these pictures are original from the complete set with red felt banners. Picture of the complete set is on the right. This set includes the darker color shades of blues and yellows and the goblets are a little bit green, but these color differences could be just a coincidence.
Majesty has 'Made in Hong Kong' stamped on her hooves.
Majesty wearing all 4 ribbons
Spike (this specific item came with the set described in this section)
Blue damsel hat with original elastic (in this pic without the ribbons)
Blue damsel hat with original elastic and 2 of the ribbons
Accessory Comparison Pictures of US Dream Castle and Euro Dream Castle
There are 4 accessory items that are undeniably different in the Euro Dream Castle described over here. In these pictures they are compared to the corresponding items from US Dream Castle set:
The Euro Dream Castle described over here includes the darker color shades of blues and yellows and the goblets are a little bit green, but these color differences could be just a coincidence.
Italian Dream Castle
Italy - Ca*Stell
Spike (not sure if this is the right variant for Italian Dream Castle)
Lavender Dream Castle
This set was released in 1989 ( Year 7). The major difference with this release is that the castle is now a lavender colour and the colour of the accessories has changed. Also spike has changed to a different shade or purple with this release.
The box the Lavender Castle came in was very similar to the box the pink castle was came in. This box had the same image (ie of the pink castle, rather then the lavender one it actually contained), but with small text "Colors of product are different from those shown.". Also, the box was slightly smaller.
It came with:
Spike the dragon (Brighter purple and green)
Argentinian Party plates with Sugarberry and Dream Castle
Argentinian Party plates with Dream Castle and various ponies
Argentinian Party plates (back)
Argentinian Loot Bag with Sugarberry and Dream Castle
Swedish Press and Peel Stickers with Tickle, Firefly, and Dream Castle