A treasure must not be found even if its place is known unless the person that finds it can protect it from thieves by taking the example in surah Al-Kahn in consideration. It’s said that secrets and treasures of the pyramids will be discovered by Al-Mahdi. 

18:77 Al-Kahf

فَانْطَلَقَا حَتَّىٰ إِذَا أَتَيَا أَهْلَ قَرْيَةٍ اسْتَطْعَمَا أَهْلَهَا فَأَبَوْا أَنْ يُضَيِّفُوهُمَا فَوَجَدَا فِيهَا جِدَارًا يُرِيدُ أَنْ يَنْقَضَّ فَأَقَامَهُ ۖ قَالَ لَوْ شِئْتَ لَاتَّخَذْتَ عَلَيْهِ أَجْرًا

So they set out, until when they came to the people of a town, they asked its people for food, but they refused to offer them hospitality. And they found therein a wall about to collapse, so he (al-Khidh) restored it. [Moses] said, "If you wished, you could have taken for it a payment."

18:82 Al-Kahf

‎وَأَمَّا الْجِدَارُ فَكَانَ لِغُلَامَيْنِ يَتِيمَيْنِ فِي الْمَدِينَةِ وَكَانَ تَحْتَهُ كَنْزٌ لَهُمَا وَكَانَ أَبُوهُمَا صَالِحًا فَأَرَادَ رَبُّكَ أَنْ يَبْلُغَا أَشُدَّهُمَا وَيَسْتَخْرِجَا كَنْزَهُمَا رَحْمَةً مِنْ رَبِّكَ ۚ وَمَا فَعَلْتُهُ عَنْ أَمْرِي ۚ ذَٰلِكَ تَأْوِيلُ مَا لَمْ تَسْطِعْ عَلَيْهِ صَبْرًا

And as for the wall, it belonged to two orphan boys in the city, and there was beneath it a treasure for them, and their father had been righteous. So your Lord intended that they reach maturity and extract their treasure, as a mercy from your Lord. And I did it not of my own accord. That is the interpretation of that about which you could not have patience."