Atop the Sandias, a mysterious dome comes into view. With caves in it.

I know the vista from the top of the Sandias pretty well by now, the jagged ridges sloping away on either side.

Today, that view opened to reveal something I’d never seen, and I couldn’t take my eyes off it.

We were skirting the edge of the mountain a couple miles north of the Sandia Crest House.

We saw the ridges. We saw rugged Juan Tabo Canyon far below. But in front of Juan Tabo Canyon, just coming into view, was a giant stone dome.

The structure rose thumblike, enormous, in front of us. It looked like it topped out nearly as high as our trail – 10,000 feet. Evergreens dotted the dome. We spotted a cave in it, then another partly obscured behind trees.

We took one of many narrow paths pulling us off the Crest Trail, closer to the mountain’s edge. A broad limestone shelf, the Del Agua Overlook, opened up. From it, an unobstructed view of the dome.

We must have sat there for half an hour, watching light and shadow play across the dome as clouds scuttled across the sun.

I thought I saw a person standing very precariously on the dome’s pitched face, a person with a white hat and black clothing. My husband busted out the binoculars and observed that the white item was a giant bird shit.

“What shat that?! A pterodactyl?”

“Maybe an eagle,” he said. “Or a vulture.”

There was plenty more to look at – swifts hurtling by us, butterflies alighting on limestone, shadows on the mountain’s green peaks. We could see other things we’d never seen from the top of the Sandias, too: the water in the Rio Grande caught my naked eye. Through the binoculars, my husband saw the Los Poblanos Fields open space.

But no matter where I looked, the dome always lured my gaze back.

I couldn’t believe after nine years of living in Albuquerque and three years of hiking here, I had never seen this incredible sight.

Just 90 minutes earlier, I’d thought the day was a wash. The Ellis Trail, where we’d started out, was in full sun. Even at 10,000 feet, it was unbearable, and I quickly turned back. I’d had no idea what direct midsummer sunlight felt like at that altitude; most of my trips to 10,000 feet, even in summer, had been cold enough to need a hoodie.

I was irked that I’d burned time and energy there before switching to the shade of the Crest Trail. I thought I’d be lucky to see anything new today.

Little did I know a magical mystery dome awaited.

After looking it up, I think the dome has to be the top of the Sandias’ famous Needle rock formation – if so, seeing its giant base from below is a completely different experience from seeing the top of it from above.

Hike length: 5 miles

Difficulty: moderate

Trail traffic: moderate

Wildlife spotted: swifts, vulture, many kinds of butterflies, brown creepers, a mule deer on the Crest Highway