You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Buddhism

Context:
The above are further subdivided into 31 planes of existence.[web 4] Rebirths in some of the higher heavens, known as the Śuddhāvāsa Worlds or Pure Abodes, can be attained only by skilled Buddhist practitioners known as anāgāmis (non-returners). Rebirths in the Ārūpyadhātu (formless realms) can be attained by only those who can meditate on the arūpajhānas, the highest object of meditation.

Question:
What is another name for Ārūpyadhātu?

formless realms