Q:

Download and Browse Sentinel data from AWS

It's been a while since I downloaded or browsed Sentinel data in AWS from http://sentinel-s2-l1c.s3-website.eu-central-1.amazonaws.com/tiles/
But I can not access this website anymore. Is it closed or is there any AWS link that does the same?

A:

The error message is:
403 Forbidden
Code: AccessDenied
Message: Requester Pays Enabled. 
etc.

Which means Sinergise (the company that owns that bucket) have configured the bucket to be a Requester Pays bucket.
From the Sentinel-Hub forum:

End of June we will set S2 L1C bucket as “Requester pays” similarly as it is for S2 L2A and S1 GRD. This move is required to allow further increase of the shared data - for continuation of Sentinel-2 L1C coverage, to accommodate global rollout of Sentinel-2 L2A and to host European and then global Sentinel-2 analysis ready mosaics.

From the AWS doc:

In general, bucket owners pay for all Amazon S3 storage and data
  transfer costs associated with their bucket. A bucket owner, however,
  can configure a bucket to be a Requester Pays bucket. With Requester
  Pays buckets, the requester instead of the bucket owner pays the cost
  of the request and the data download from the bucket. The bucket owner
  always pays the cost of storing data.
Typically, you configure buckets to be Requester Pays when you want to
  share data but not incur charges associated with others accessing the
  data. You might, for example, use Requester Pays buckets when making
  available large datasets, such as zip code directories, reference
  data, geospatial information, or web crawling data.
Important
If you enable Requester Pays on a bucket, anonymous access to that
  bucket is not allowed.

So to access this Sentinel L2C data, you need to be logged in to an AWS account and accept the data transfer charges, there are details about how to do this in the Sentinel-Hub forum topic
The EO Browser links to this user pays AWS bucket but also provides links to the ESA SciHub data store where you can download the data for free (you need a SciHub account).

