Is nirvana a mere conscious experience, and if so of what kind?

Nirvana is not a place like heaven to experience. Its merely seeing the world as is without the wale of Moha blocking our view. When you attain Sopadisesa Nirvana you get to see the process that binds you to Sansara, and in that, you realize there is nothing worth clinging onto, thus removing the reasons to Bhawa (simply means rebirth). So, at Anupadisesa Nirvana, when your body dies, there there will be no rebirth for you, thus breaking the cycle of birth and death (sansara).

Due to Moha, we never get to experience the world as is. Everything we do, is targeted towards building the concept of 'myself'. In this conceptual world we build ourselves with 'myslef' at the center, we form attachments of Lobha (attraction), Dwesha (desisting) or neither Lobha nor Dwesha.

• If we take Lobha attachments, the 'self' is ascertained by thinking that something is good for 'me'.
• If we take Dwesha attachments, the 'self' is ascertained by thinking that something is bad for 'me'.
• If we take neither Lobha nor Dwesha attachments, the 'self' is ascertained by thinking that something is neither good nor bad for 'me'.

This is a very tiresome thing for all of us, but we do not know any better. We simply do this over and over when interacting or identifying anything in the world, and build up the conceptual world within our mind accordingly. This is why we never see the reality. We always see a reflection of our own mind.

If you take your own body, how many aches and pains are there? How many diseases are there? Don't you fear of getting diseases in the future? You may not be happy of your weight, height, muscle structure, metabolic rate, body odor, hair, etc. Even to maintain your body you have to feed it, bathe it, dress it, tend to its needs. Even if you do them all today, your tasks are not done. You need to repeat them tomorrow, the day after, and until you die. Lord Budhdha shows us that it will not be over even after death. Because we are bound to Sansara, we will receive another body to maintain, fear, care, hate, or like. As long as there is someone (sakkhaya dhitti) they will face suffering (dukhkha).

According to Lord Budhdha, there are 31 plains of existence, 31 plains where we can be reborn. And we have no control over that. These plains have different kind of bodies and minds. In some plains there are lifespans of eons. Whatever the plain you are born, as long as there is someone they will face suffering (dukhkha).

Nirvana is the end of this endless cycle. There is no one to suffer at Nirvana. That's why its a bliss.

Note: When Nirvana is realized in this life with the body remaining, it is called Sopadisesa nibbana-dhatu. When an Arahat attains Parinibbana, after the dissolution of his body, without any remainder of physical existence it is called Anupadisesa nibbana-dhatu.

There is suffering. It's not your suffering or my suffering. It's simply mental suffering that arises whenever the mind-body phenomena is mired in craving and clinging, that is rooted in ignorance.

Through the cultivation of wisdom through the noble eightfold path, ignorance is weakened and eventually uprooted. When ignorance is uprooted, craving is ended and this brings the permanent cessation of suffering. With the awakening from ignorance, comes the liberation from suffering.

Upon liberation from suffering, Nirvana is experienced. The clinging aggregates are destroyed but the non-clinging aggregates survive until the dissolution of the physical body. This is called Nirvana element with fuel remaining.

Nirvana is a phenomena or thing that is sensed by the mind when it is completely free from suffering. It is the experience of the absence of suffering. It can be cognized by mind-consciousness. It's not a thought. It's not an emotion. It's not consciousness. It's not a state of mind. It is unchanging and it is not self. Of course, due to the experience of Nirvana, peace and bliss can arise and be felt as emotions.

Imagine that you were a soldier in South East Asia during World War 2. One day you ran deep into the forest to escape the pursuit of the enemy. Since then, you lived in hiding with fear and anxiety, constantly looking out for enemy incursion, day and night, day after day. You spend decades deep in the woods with mental anguish, depression, boredom, loneliness, fear and anxiety. All sorts of mental suffering.

Then one day, some people discover you in the forest and tell you not to be afraid, and that WW2 had ended decades ago. There's no war anymore. No enemies. Only peace.

Becoming awakened to the fact that the war had ended, which is uprooting the ignorance of the fact that the war had ended, causes the ending of clinging to the mindset (or mental concept or mental world) of living in hiding from the war. And with the ending of this clinging, comes the cessation of mental suffering. No more fear and anxiety.

You experience a huge burden lifted, a sense of relief, a source of peace and bliss. That's not a thought or emotion of the mind. That's not consciousness. That's not a state of mind. That is a phenomena which is experienced by the mind. That is a phenomena cognized by mind-consciousness. That is the experience of the absence of suffering.

This is an analogy to explain what Nirvana is.

Of course, the WW2 soldier's freedom from suffering is not permanent. It would soon get replaced with some other suffering. The permanent achievement of Nirvana on the other hand, brings permanent freedom from suffering.

Ven. Sariputta: “Reverends, extinguishment (Nibbana) is bliss!

Ven. Udayi: “But Reverend Sāriputta, what’s blissful about it, since nothing is felt?”

Ven. Sariputta: “The fact that nothing is felt is precisely what’s blissful about it.

AN 9.34