Right. Of course there is.

He steps down and, once he's definitely out of sight of the outside, uses a light cantrip to conjure a heatless torch-light in his cupped palm.

The basement is almost a copy of the room upstairs, except the walls are made of stone, and the history writ upon them is older.

Instead of a proper altar, there is a blank slap occupying the space at the bag. He might notice a nagging feeling of missing something when his gazes crosses it.

A very obvious illusion spell? Writing that's invisible until an activation phrase, or a specific person looks at it - 

Or someone with a special trait like the sharingan.

...Or someone who can cast read magic. This might give him a horrible headache and probably won't work - it wouldn't be enough to see through illusory scripts in his own world - but that and detect magic might work together enough to heighten what little he can pierce together.

There's something there, he can almost see the outline of a seal... He just needs to try a little harder-

There's a pressure building up in his head behind his eyes, pulsing out of time with his heartbeat.

He concentrates, and the detection spells get more powerful the longer you focus on them - 

Almost, almost-

His eyes feel like they're going to explode out of his head. He feels an instinct to push chakra at them.

He does so.

The world blurs and spins, faintly tinged with red-

-then snaps into focus, sharper than ever. On the wall he can see the design of a seal, two concentric circles with a dot in the middle. Three comma-shaped marks are spaced equidistant around the inner ring and four lines of sealwork form a cross centered on the dot. This is a lock, visible only to those with the sharingan. He sees that to open it, he needs to coat his hand in fire-natured chakra and trace the characters meaning samsara, the cycle of life and death.

...He is not going to do that until he actually knows how to consistently mold fire chakra, which should probably come after being able to consistently mold his own actual lightning affinity. It's been here a while, it's unlikely to go anywhere, though there's a good chance he can manage at least some fire today or tomorrow...

He goes back through the basement, resets the trapdoor as carefully as he can, inscribing the same mark as is on the entrances in his apartment (which doesn't prevent someone from opening them, merely alerts him if it is) along the inside edge. He then walks through the shrine, and if nothing else jumps out with the sharingan's edition, he crouches by the back corner of the exterior, in a little place hidden within the overgrown rock garden, and inscribes a few marks along the bottom edge in the stones - carefully not in his usual hand-writing.

And then he deactivates the sharingan and heads to practice.

Kakashi is only a little late. Today is jutsu day, as promised. Essentially, they'll be doing a weaponized version of the exercises from yesterday, using more chakra and projecting it further. Chihiro and Naruto will be practicing a wind blade on the dummies Kakashi sets up, while Sasuke does the same thing as yesterday but with a non-conductive target.

Right.

He practices that for a bit, gets the basics down, since that was the assignment. Then, to Kakashi: "What's the exercise for fire chakra?"

"Already planning your next element? Most people like a little more focus."

"Found a thing that I think needs steady fire chakra. Just - enough to channel it."

He should probably actually tell Kakashi about the seal before trying to open it, in case it explodes on him. First rule of exploring weird ruins: always have a healer out of probable trap range when messing with blatant magic. (Helps that Sugira doesn't give a rat's ass about clan secrets.)

"The Uchiha do love their fire. Okay." With fire nature chakra, you sort of knead the warmth into it. Then gather it in the mouth and breath it out. Kakashi demonstrates with a small puff of flame, like blowing a smoke ring.

"Would holding it in my hand be harder, then? - Also, I activated the sharingan. Would that help?"

"...It'll save me having to explain it more, at least. Turn it on and then just, uh, do what I do."

He does so.

Kakashi demonstrates again. It's pretty obvious how he's doing it. Sugira should have little trouble replicating it.

He copies that, then.

"Almost like cheating, isn't it?"

He squints. "...I think I'm intensely suspicious of any magic system this easy that isn't promptly exploding. Or costing limbs." Where's the narratively interesting complications. There are always narratively interesting complications, even if just 'it's weirdly hard to bring clothes with you when teleporting.'

"Well, just because you can see how to do something doesn't mean you actually can do it. Be careful of techniques that cost more chakra than you have, or moves that need more speed than you can exert."

He nods.

"...Speaking of exploding. I'm - not sure the thing I found is safe."

"Where did you find it?"

"In the compound. Hidden room."