STUPA , The Tibetan word is Chorten, which means "the basis of offering". It is a symbol of enlightened mind, (the awakened mind, universal divinity) and the path to its realisation.
If you had to use just two words, the best definition I have seen is "Spiritual Monument". The stupa represents the Buddha's body, his speech and his mind, but most especially his mind and every part shows the path to Enlightenment.
During our travel to Nepal , some time we find some intresting stuff, among them is this beautiful copper hand made STUPA which you can use as Incense burner. This Stupa can be open. There is a place for burning incense. This stupa is hand made and very well done. On the top of The Stupa there is a small window where you can see small image of Buddha.
Left pictres is Dharma Dhatu.
READ more about WHAT IS STUPA ?